Test method, device and equipment of business system and storage medium

Abstract

The present disclosure provides a test method and device of a business system, equipment and a storage medium, relates to the field of data processing, in particular to the field of data testing. The specific implementation scheme is: based on log information of a data layer of the business system, obtaining incremental data under a test behavior; based on the incremental data and expected data corresponding to the test behavior, obtaining a verification result of the data layer; based on the verification result of the data layer, obtaining a first verification result of an interface service provided by a service layer of the business system; wherein the service layer is used for calling the interface service for processing based on the test behavior, and the data layer is used for storing processing data of the interface service. According to the technology of the present disclosure, the test process is simplified, and the test efficiency is improved.

Description

Technical Field

[0001] This disclosure relates to the field of data processing technology, and more particularly to the field of data testing technology. Background Technology

[0002] In traditional business system testing models, testers mostly validate the interface services of the service layer, that is, they determine whether the test behavior was successful based on the interface service logs. However, a single test request may call multiple interface services in the service layer, which requires validating a large number of logs, making the testing process lengthy and reducing testing efficiency. Summary of the Invention

[0003] This disclosure provides a testing method, apparatus, device, and storage medium for a business system.

[0004] According to one aspect of this disclosure, a testing method for a business system is provided, comprising:

[0005] Incremental data for test behaviors is obtained based on log information from the data layer of the business system.

[0006] Based on the incremental data and the expected data corresponding to the test behavior, the verification results of the data layer are obtained;

[0007] Based on the verification results of the data layer, the first verification result of the interface service provided by the service layer of the business system is obtained; wherein, the service layer is used to call the interface service for processing based on the test behavior, and the data layer is used to store the processing data of the interface service.

[0008] According to another aspect of this disclosure, a business system testing apparatus is provided, comprising:

[0009] The determination module is used to obtain incremental data under test behavior based on the log information of the data layer of the business system;

[0010] The data layer verification module is used to obtain the verification results of the data layer based on the incremental data and the expected data corresponding to the test behavior.

[0011] The processing module is used to obtain the first verification result of the interface service provided by the service layer of the business system based on the verification result of the data layer; the service layer is used to call the interface service for processing based on the test behavior, and the data layer is used to store the processing data of the interface service.

[0012] According to another aspect of this disclosure, an electronic device is provided, comprising:

[0013] At least one processor; and

[0014] A memory that is communicatively connected to at least one processor; wherein,

[0015] The memory stores instructions that can be executed by at least one processor, which enables the at least one processor to perform any of the business system testing methods in the embodiments of this disclosure.

[0016] According to another aspect of this disclosure, a non-transitory computer-readable storage medium storing computer instructions is provided, wherein the computer instructions are used to cause a computer to execute any of the business system testing methods in the embodiments of this disclosure.

[0017] According to another aspect of this disclosure, a computer program product is provided, including a computer program that, when executed by a processor, implements any of the business system testing methods described in the embodiments of this disclosure.

[0018] The technical solution according to the embodiments of this application can improve testing efficiency.

[0019] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0020] The accompanying drawings are provided to better understand this solution and do not constitute a limitation of this disclosure. Wherein:

[0021] Figure 1 This is a flowchart of a business system testing method according to an embodiment of the present disclosure;

[0022] Figure 2 This is a schematic diagram of a business system according to an embodiment of the present disclosure;

[0023] Figure 3 This is a flowchart of step S101 in a business system testing method according to an embodiment of the present disclosure;

[0024] Figure 4 This is a schematic diagram illustrating data distribution using a data incremental awareness service according to an embodiment of the present disclosure;

[0025] Figure 5 This is a schematic diagram illustrating the interaction between a data incremental awareness service and a data layer according to an embodiment of this disclosure;

[0026] Figure 6 This is a detailed flowchart of a business system test according to an embodiment of the present disclosure;

[0027] Figure 7 This is a block diagram of a business system testing apparatus according to an embodiment of the present disclosure;

[0028] Figure 8 This is a block diagram of a business system testing apparatus according to another embodiment of the present disclosure;

[0029] Figure 9 This is a block diagram of an electronic device used to implement the business system testing method of the embodiments of this disclosure. Detailed Implementation

[0030] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0031] Figure 1 This is a flowchart of a business system testing method according to an embodiment of this disclosure. Figure 1 As shown, the method may include:

[0032] S101. Based on the log information of the data layer of the business system, obtain incremental data under the test behavior;

[0033] S102. Based on the incremental data and the expected data corresponding to the test behavior, obtain the verification results of the data layer;

[0034] S103. Based on the verification result of the data layer, obtain the first verification result of the interface service provided by the service layer of the business system; wherein, the service layer is used to call the interface service for processing based on the test behavior, and the data layer is used to store the processing data of the interface service.

[0035] For example, such as Figure 2 As shown, the architecture of the business system largely includes: a UI (User Interface) layer, a service layer, and a data layer. The user interface layer presents an executable interface to the user through a device terminal (such as a computer, mobile phone, or tablet). For example, during testing, the user can perform related operations on the interface (i.e., test behavior), and the business system generates corresponding interface service requests based on these operations. The service layer is used to call interface services for processing based on the test behavior. For example, when the service layer receives an interface service request, it calls the corresponding service module interface according to the request and returns the request response information to the user interface layer, enabling the user interface layer to draw and render the page. The data layer stores the processing data for the interface services. For example, when the service layer calls an interface service, it performs related operations (such as query operations, update operations, and delete operations) on the database in the data layer, thereby the service layer calls the data in the data layer to generate request response information. In this embodiment, the database can be a MySQL database.

[0036] In step S101, for example, the log information of the data layer can record modified data in the data layer. Therefore, when the business system is being tested, after a user performs a test action at the user interface layer, all changes to the data in the data layer will be recorded in the log information. Thus, by querying the log information, the incremental data under the test action can be determined.

[0037] In step S102, for example, each test behavior has corresponding expected data in the data layer, wherein the expected data refers to the data generated in the database during test execution when the service layer provides the expected service interface according to the test behavior.

[0038] Furthermore, if the incremental data is the same as the expected data, the data layer passes the validation; if the incremental data is different from the expected data, the data layer fails the validation, and testers need to further determine the reason for the failure. Alternatively, testers can directly determine whether the incremental data matches the expected data to obtain the validation result of the data layer.

[0039] In step S103, for example, since the user's operation on the operation interface is ultimately reflected in the operation on the data layer, if the data layer passes the verification, it can be determined that the service module interface providing the interface service in the service layer has passed the verification, thereby reducing the verification of the logs of the interface service in the service layer.

[0040] In this disclosed technical solution, incremental data under test behavior is determined based on log information from the data layer. The verification result of the data layer is then obtained based on this incremental data, thus ensuring the sufficiency of the data layer verification. Furthermore, since the data layer stores the processing data of the interface service, and the service layer calls the interface service for processing based on the test behavior, the first verification result of the interface service provided by the service layer of the business system can be determined based on the verification result of the data layer. This eliminates the need for extensive verification of log information in the service layer, enabling verification of the service layer, simplifying the testing process, improving testing efficiency, and reducing personnel costs.

[0041] In one implementation, such as Figure 3 As shown, based on the log information of the business system's data layer, incremental data under test behavior is obtained, including:

[0042] S301. Use the incremental data awareness service to parse the log information of the data layer to obtain the incremental data in the data layer;

[0043] S302. Based on the test user identifier and / or data type corresponding to the test behavior, filter the incremental data in the data layer to obtain the incremental data under the test behavior.

[0044] For example, such as Figure 4As shown, the incremental data awareness service is used to capture incremental changes in the data layer. It can perform real-time sensing and parsing of binlog (binary log file) logs generated by the MySQL database. It should be noted that the incremental data awareness service supports multiple testing scenarios, can simultaneously acquire incremental data from multiple data layers, and push the incremental data corresponding to each data layer to the corresponding test process.

[0045] For example, the user identifier can be a user ID, or it can be other forms of representation. For instance, if tester 1 and tester 2 are simultaneously testing on the business system, the user ID marking tester 1's test behavior is 1, and the user ID marking tester 2's test behavior is 2. After determining the incremental data in the data layer, testers can filter the incremental data based on the user ID, filtering out data that they don't need (i.e., accurately filtering out the incremental data generated by test behaviors under that user ID), thereby avoiding the problem of test data interference. Even if multiple testers work simultaneously, the accuracy of the test can be guaranteed, thus effectively improving the accuracy and efficiency of the test.

[0046] For example, the data type can be represented by the service module called in the service layer according to the current test behavior. For instance, if the current test behavior calls service module A, service module B, and service module C in the service layer, then the data type corresponding to the current test behavior is A, B, and C, respectively. For example, if the number of tester IDs is small, duplicate user IDs can easily occur when multiple testers perform tests. Therefore, the data type corresponding to each test behavior can be marked in the service layer. After determining the incremental data in the data layer, testers can filter the incremental data according to the data type, filtering out data that they don't need, thereby avoiding test data interference and effectively improving the accuracy and efficiency of testing.

[0047] For example, after identifying the incremental data in the data layer, the incremental data can be filtered simultaneously based on user identifier and data type, thus enabling more accurate filtering. Furthermore, after filtering the incremental data, the resulting filtered data is formatted (see the table below) to ensure a consistent format. This facilitates comparison of the incremental data and enables verification of the data layer.

[0048]

[0049] In one embodiment, the method further includes:

[0050] Based on the socket connection between the incremental data awareness service and the data layer, preset instructions are sent to the data layer; these preset instructions are used to indicate the incremental synchronization point of the test behavior.

[0051] Based on the incremental data awareness service, log information pushed by the data layer of the business system based on incremental synchronization points is received.

[0052] In this embodiment, as Figure 5 As shown, the incremental data awareness service establishes a socket connection with the data layer, confirms its identity through a handshake protocol, and obtains the database's IP address (Internet Protocol), port number, username, and password. Based on this information, the incremental data awareness service registers itself as a slave database of the data layer. It sends a binlog dump command (i.e., a preset instruction) to the data layer, using the current time of command transmission as the incremental synchronization point, and pushes log information generated in the data layer after the current time to the incremental data awareness service. This avoids the problem of manually querying and verifying the data layer in existing technologies, and allows direct access to all data increments under test operations through the incremental data awareness service, ensuring the sufficiency of data layer verification.

[0053] In one implementation, the system receives log information pushed by the data layer of the business system based on incremental synchronization points, according to the incremental data awareness service, including:

[0054] Based on the incremental data awareness service and master-slave replication protocol, the data layer of the business system receives log information pushed based on incremental synchronization points.

[0055] In this embodiment, after sending a binlog dump command (i.e., a preset instruction) to the data layer, the current moment of sending the command is used as the incremental synchronization point. The rowlevel logs continuously pushed from the database are obtained through the master-slave replication protocol. Since the master-slave replication protocol can receive log information more accurately, and since the rowlevel log content clearly records the details of each row data modification, the incremental data can be accurately determined.

[0056] In one embodiment, the method further includes:

[0057] Based on the log information of the service layer, the second verification result of the interface service provided by the service layer is obtained;

[0058] And / or,

[0059] Based on the display information of the business system, the validation result of the user interface layer of the business system is obtained.

[0060] In this embodiment, core service modules in the service layer are pre-determined for each business system. To ensure the accuracy of core service module testing, when a core service module interface needs to be called, the service layer needs to verify the core service module interface again based on the service layer's log information. Non-core service module interfaces do not need to be verified. This not only ensures the accuracy of service layer testing but also reduces the workload of service layer testing and improves testing efficiency.

[0061] In this embodiment, since the business system includes a user interface layer, a service layer, and a data layer, when testing the business system based on testing behavior, the user interface layer, service layer, and data layer are verified separately, thereby comprehensively testing the business system.

[0062] For example, such as Figure 6 As shown, on one hand, when the user interface layer receives request-response information, it renders the information on the user interface layer and then judges whether the user interface layer meets expectations based on the content presented (i.e., the displayed information). On the other hand, it identifies the core service modules in the service layer that are being called and verifies the service layer based on the service layer's log information. Furthermore, it determines the incremental data in the data layer based on the incremental data awareness service, then filters the incremental data according to the testers' requirements, formats the filtered incremental data, and then checks whether the formatted incremental data meets expectations. This completes the testing of the business system. It should be noted that data verification of the user interface layer, service layer, and data layer can be automated or manual; this is not limited here.

[0063] Figure 7 This is a block diagram of a business system testing apparatus according to an embodiment of the present disclosure. Figure 7 As shown, the device may include:

[0064] Module 701 is used to obtain incremental data under test behavior based on the log information of the data layer of the business system.

[0065] The data layer verification module 702 is used to obtain the verification result of the data layer based on the incremental data and the expected data corresponding to the test behavior;

[0066] The processing module 703 is used to obtain the first verification result of the interface service provided by the service layer of the business system based on the verification result of the data layer; wherein, the service layer is used to call the interface service for processing based on the test behavior, and the data layer is used to store the processing data of the interface service.

[0067] In one implementation, such as Figure 8 As shown, module 803 includes:

[0068] Parsing unit 804 is used to parse the log information of the data layer using the data incremental awareness service to obtain the incremental data in the data layer;

[0069] The filtering unit 805 is used to filter incremental data in the data layer based on the test user identifier and / or data type corresponding to the test behavior, so as to obtain incremental data under the test behavior.

[0070] In one implementation, such as Figure 8 As shown, the device also includes:

[0071] The sending module 801 is used to send preset instructions to the data layer based on the socket connection between the incremental data awareness service and the data layer; wherein, the preset instructions are used to indicate the incremental synchronization point of the test behavior;

[0072] The receiving module 802 is used to receive log information pushed by the data layer of the business system based on the incremental synchronization point based on the data incremental awareness service.

[0073] In one implementation, the receiving module 802 is further configured to receive log information pushed by the data layer of the business system based on incremental synchronization points, based on the data incremental awareness service and the master-slave replication protocol.

[0074] In one implementation, such as Figure 8 As shown, the device also includes:

[0075] The service layer testing module 808 is used to obtain the second verification result of the interface service provided by the service layer based on the log information of the service layer;

[0076] And / or,

[0077] The interface layer testing module 809 is used to obtain the verification results of the user interface layer of the business system based on the display information of the business system.

[0078] Thus, the apparatus of this embodiment determines incremental data under test behavior based on log information from the data layer, and obtains the verification result of the data layer based on the incremental data, thereby ensuring the sufficiency of data layer verification. Furthermore, since the data layer stores processing data for interface services, and the service layer calls interface services for processing based on test behavior, the first verification result of the interface service provided by the service layer of the business system can be determined based on the verification result of the data layer. Verification of the service layer can be achieved without extensive verification of log information in the service layer, simplifying the testing process, improving testing efficiency, and reducing personnel costs.

[0079] The acquisition, storage, and application of user personal information involved in the technical solution disclosed herein comply with the provisions of relevant laws and regulations and do not violate public order and good morals.

[0080] According to embodiments of this disclosure, this disclosure also provides an electronic device, a readable storage medium, and a computer program product.

[0081] Figure 9 A schematic block diagram of an example electronic device 900 that can be used to implement embodiments of the present disclosure is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0082] like Figure 9 As shown, device 900 includes a computing unit 901, which can perform various appropriate actions and processes based on a computer program stored in read-only memory (ROM) 902 or a computer program loaded into random access memory (RAM) 903 from storage unit 908. RAM 903 may also store various programs and data required for the operation of device 900. The computing unit 901, ROM 902, and RAM 903 are interconnected via bus 904. Input / output (I / O) interface 905 is also connected to bus 904.

[0083] Multiple components in device 900 are connected to I / O interface 905, including: input unit 906, such as keyboard, mouse, etc.; output unit 907, such as various types of monitors, speakers, etc.; storage unit 908, such as disk, optical disk, etc.; and communication unit 909, such as network card, modem, wireless transceiver, etc. Communication unit 909 allows device 900 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0084] The computing unit 901 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 901 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 901 performs the various methods and processes described above, such as business system testing methods. For example, in some embodiments, the business system testing method may be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 908. In some embodiments, part or all of the computer program may be loaded and / or installed on device 900 via ROM 902 and / or communication unit 909. When the computer program is loaded into RAM 903 and executed by the computing unit 901, one or more steps of the business system testing method described above may be performed. Alternatively, in other embodiments, the computing unit 901 may be configured to perform business system testing methods by any other suitable means (e.g., by means of firmware).

[0085] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0086] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0087] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0088] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0089] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as a data server), or computing systems that include middleware components (e.g., an application server), or computing systems that include frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with embodiments of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication network). Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0090] Computer systems can include clients and servers. Clients and servers are generally located far apart and typically interact via communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other. Servers can be cloud servers, servers in distributed systems, or servers incorporating blockchain technology.

[0091] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0092] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for testing a business system, comprising: obtaining incremental data under a test behavior based on log information of a data layer of the business system; obtaining a verification result of the data layer based on the incremental data and expected data corresponding to the test behavior; obtaining a first verification result of an interface service provided by a service layer of the business system based on the verification result of the data layer, wherein the service layer is configured to invoke the interface service for processing based on the test behavior, and the data layer is configured to store processing data of the interface service; wherein the obtaining of the incremental data under the test behavior based on the log information of the data layer of the business system comprises: parsing the log information of the data layer by using a data incremental awareness service to obtain incremental data in the data layer; and filtering the incremental data in the data layer based on a test user identifier and / or a data type corresponding to the test behavior to obtain the incremental data under the test behavior. 2.The method of claim 1, further comprising: sending a preset instruction to the data layer based on a socket connection between a data incremental awareness service and the data layer, wherein the preset instruction is configured to indicate an incremental synchronization point of the test behavior; and receiving log information pushed by the data layer of the business system based on the incremental synchronization point based on the data incremental awareness service.

3. The method of claim 2, wherein, The receiving of the log information pushed by the data layer of the business system based on the incremental synchronization point based on the data incremental awareness service comprises: receiving the log information pushed by the data layer of the business system based on the incremental synchronization point based on the data incremental awareness service and a master-slave replication protocol. 4.The method of any one of claims 1-3, further comprising: obtaining a second verification result of the interface service provided by the service layer based on log information of the service layer; and / or obtaining a verification result of a user interface layer of the business system based on display information of the business system. 5.A device for testing a business system, comprising: a determination module configured to obtain incremental data under a test behavior based on log information of a data layer of the business system; a data layer verification module configured to obtain a verification result of the data layer based on the incremental data and expected data corresponding to the test behavior; a processing module configured to obtain a first verification result of an interface service provided by a service layer of the business system based on the verification result of the data layer, wherein the service layer is configured to invoke the interface service for processing based on the test behavior, and the data layer is configured to store processing data of the interface service; wherein the determination module comprises: a parsing unit configured to parse the log information of the data layer by using a data incremental awareness service to obtain incremental data in the data layer; and a filtering unit configured to filter the incremental data in the data layer based on a test user identifier and / or a data type corresponding to the test behavior to obtain the incremental data under the test behavior. 6.The device of claim 5, further comprising: ​ The sending module is configured to send a preset instruction to the data layer based on a socket connection between the data incremental awareness service and the data layer, wherein the preset instruction is used to indicate an incremental synchronization point of the test behavior. The receiving module is configured to receive log information pushed by the data layer of the business system based on the incremental synchronization point based on the data incremental awareness service.

7. The apparatus of claim 6, wherein, The receiving module is further configured to receive log information pushed by the data layer of the business system based on the incremental synchronization point based on the data incremental awareness service and the master-slave replication protocol.

8. The apparatus of any one of claims 5-7, further comprising: a service layer test module configured to obtain a second verification result of an interface service provided by the service layer based on the log information of the service layer; and / or, an interface layer test module configured to obtain a verification result of a user interface layer of the business system based on the display information of the business system.

9. An electronic device, comprising: at least one processor; and a memory connected to the at least one processor in communication; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 1-4.

10. A non-transitory computer readable storage medium having stored thereon computer instructions, wherein, The computer instructions are used to enable the computer to perform the method of any one of claims 1-4.

11. A computer program product comprising a computer program which, when executed by a processor, implements the method of any one of claims 1-4.

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