M. Marcozzi, Sébastien Bardin, Mickaël Delahaye, N. Kosmatov, V. Prevosto
Automated white-box testing is a major issue in software engineering. In previous work, we introduced LTest, a generic and integrated toolkit for automated white-box testing of C programs. LTest supports a broad class of coverage criteria in a unified way (through the label specification mechanism) and covers most major parts of the testing process – including coverage measurement, test generation and detection of infeasible test objectives. However, the original version of LTest was unable to handle several major classes of coverage criteria, such as MCDC or dataflow criteria. Moreover, its practical applicability remained barely assessed. In this work, we present a significantly extended version of LTest that supports almost all existing testing criteria, including MCDC and some software security properties, through a native support of recently proposed hyperlabels. We also provide a more realistic view on the practical applicability of the extended tool, with experiments assessing its efficiency and scalability on real-world programs.
{"title":"Taming Coverage Criteria Heterogeneity with LTest","authors":"M. Marcozzi, Sébastien Bardin, Mickaël Delahaye, N. Kosmatov, V. Prevosto","doi":"10.1109/ICST.2017.57","DOIUrl":"https://doi.org/10.1109/ICST.2017.57","url":null,"abstract":"Automated white-box testing is a major issue in software engineering. In previous work, we introduced LTest, a generic and integrated toolkit for automated white-box testing of C programs. LTest supports a broad class of coverage criteria in a unified way (through the label specification mechanism) and covers most major parts of the testing process – including coverage measurement, test generation and detection of infeasible test objectives. However, the original version of LTest was unable to handle several major classes of coverage criteria, such as MCDC or dataflow criteria. Moreover, its practical applicability remained barely assessed. In this work, we present a significantly extended version of LTest that supports almost all existing testing criteria, including MCDC and some software security properties, through a native support of recently proposed hyperlabels. We also provide a more realistic view on the practical applicability of the extended tool, with experiments assessing its efficiency and scalability on real-world programs.","PeriodicalId":112258,"journal":{"name":"2017 IEEE International Conference on Software Testing, Verification and Validation (ICST)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129065459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhiyuan Wan, D. Lo, Xin Xia, Liang Cai, Shanping Li
A container is a group of processes isolated from other groups via distinct kernel namespaces and resource allocation quota. Attacks against containers often leverage kernel exploits through system call interface. In this paper, we present an approach that mines sandboxes for containers. We first explore the behaviors of a container by leveraging automatic testing, and extract the set of system calls accessed during testing. The set of system calls then results as a sandbox of the container. The mined sandbox restricts the container's access to system calls which are not seen during testing and thus reduces the attack surface. In the experiment, our approach requires less than eleven minutes to mine sandbox for each of the containers. The enforcement of mined sandboxes does not impact the regular functionality of a container and incurs low performance overhead.
{"title":"Mining Sandboxes for Linux Containers","authors":"Zhiyuan Wan, D. Lo, Xin Xia, Liang Cai, Shanping Li","doi":"10.1109/ICST.2017.16","DOIUrl":"https://doi.org/10.1109/ICST.2017.16","url":null,"abstract":"A container is a group of processes isolated from other groups via distinct kernel namespaces and resource allocation quota. Attacks against containers often leverage kernel exploits through system call interface. In this paper, we present an approach that mines sandboxes for containers. We first explore the behaviors of a container by leveraging automatic testing, and extract the set of system calls accessed during testing. The set of system calls then results as a sandbox of the container. The mined sandbox restricts the container's access to system calls which are not seen during testing and thus reduces the attack surface. In the experiment, our approach requires less than eleven minutes to mine sandbox for each of the containers. The enforcement of mined sandboxes does not impact the regular functionality of a container and incurs low performance overhead.","PeriodicalId":112258,"journal":{"name":"2017 IEEE International Conference on Software Testing, Verification and Validation (ICST)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116768658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Emil Alégroth, Shinsuke Matsuki, T. Vos, Kinji Akemine
In the software testing contest, practitioners and researcher's are invited to test their test approaches against similar approaches to evaluate pros and cons and which is perceivably the best. The 2017 iteration of the contest focused on Graphical User Interface-driven testing, which was evaluated on the testing tool TESTONA. The winner of the competition was announced at the closing ceremony of the international conference on software testing (ICST), 2017.
{"title":"Overview of the ICST International Software Testing Contest","authors":"Emil Alégroth, Shinsuke Matsuki, T. Vos, Kinji Akemine","doi":"10.1109/ICST.2017.67","DOIUrl":"https://doi.org/10.1109/ICST.2017.67","url":null,"abstract":"In the software testing contest, practitioners and researcher's are invited to test their test approaches against similar approaches to evaluate pros and cons and which is perceivably the best. The 2017 iteration of the contest focused on Graphical User Interface-driven testing, which was evaluated on the testing tool TESTONA. The winner of the competition was announced at the closing ceremony of the international conference on software testing (ICST), 2017.","PeriodicalId":112258,"journal":{"name":"2017 IEEE International Conference on Software Testing, Verification and Validation (ICST)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117152614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Al-Nayeem, Krzysztof Ostrowski, Sebastian Pueblas, Christophe Restif, Sai Zhang
Software evolves continuously. Its behavior must be validated by engineers who perform daily development and maintenance tasks. However, despite its high importance, information needs for validating evolving software has not been systematically studied in an industrial setting. Such lack of empirical knowledge hinders attempts to understand this fundamental practice and improve the corresponding tool support. This paper presents a study on 194 Site Reliability Engineers (SREs) at Google to explore their information needs. The results suggest several directions where software engineering researchers may consider putting effort to develop new techniques and tool support that matter to practitioners.
{"title":"Information Needs for Validating Evolving Software Systems: An Exploratory Study at Google","authors":"A. Al-Nayeem, Krzysztof Ostrowski, Sebastian Pueblas, Christophe Restif, Sai Zhang","doi":"10.1109/ICST.2017.64","DOIUrl":"https://doi.org/10.1109/ICST.2017.64","url":null,"abstract":"Software evolves continuously. Its behavior must be validated by engineers who perform daily development and maintenance tasks. However, despite its high importance, information needs for validating evolving software has not been systematically studied in an industrial setting. Such lack of empirical knowledge hinders attempts to understand this fundamental practice and improve the corresponding tool support. This paper presents a study on 194 Site Reliability Engineers (SREs) at Google to explore their information needs. The results suggest several directions where software engineering researchers may consider putting effort to develop new techniques and tool support that matter to practitioners.","PeriodicalId":112258,"journal":{"name":"2017 IEEE International Conference on Software Testing, Verification and Validation (ICST)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116263428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Testing JavaScript code is important. JavaScript has grown to be among the most popular programming languages and it is extensively used to create web applications both on the client and server. We present the first empirical study of JavaScript tests to characterize their prevalence, quality metrics (e.g. code coverage), and shortcomings. We perform our study across a representative corpus of 373 JavaScript projects, with over 5.4 million lines of JavaScript code. Our results show that 22% of the studied subjects do not have test code. About 40% of projects with JavaScript at client-side do not have a test, while this is only about 3% for the purely server-side JavaScript projects. Also tests for server-side code have high quality (in terms of code coverage, test code ratio, test commit ratio, and average number of assertions per test), while tests for client-side code have moderate to low quality. In general, tests written in Mocha, Tape, Tap, and Nodeunit frameworks have high quality and those written without using any framework have low quality. We scrutinize the (un)covered parts of the code under test to find out root causes for the uncovered code. Our results show that JavaScript tests lack proper coverage for event-dependent callbacks (36%), asynchronous callbacks (53%), and DOM-related code (63%). We believe that it is worthwhile for the developer and research community to focus on testing techniques and tools to achieve better coverage for difficult to cover JavaScript code.
{"title":"JavaScript: The (Un)Covered Parts","authors":"A. M. Fard, A. Mesbah","doi":"10.1109/ICST.2017.28","DOIUrl":"https://doi.org/10.1109/ICST.2017.28","url":null,"abstract":"Testing JavaScript code is important. JavaScript has grown to be among the most popular programming languages and it is extensively used to create web applications both on the client and server. We present the first empirical study of JavaScript tests to characterize their prevalence, quality metrics (e.g. code coverage), and shortcomings. We perform our study across a representative corpus of 373 JavaScript projects, with over 5.4 million lines of JavaScript code. Our results show that 22% of the studied subjects do not have test code. About 40% of projects with JavaScript at client-side do not have a test, while this is only about 3% for the purely server-side JavaScript projects. Also tests for server-side code have high quality (in terms of code coverage, test code ratio, test commit ratio, and average number of assertions per test), while tests for client-side code have moderate to low quality. In general, tests written in Mocha, Tape, Tap, and Nodeunit frameworks have high quality and those written without using any framework have low quality. We scrutinize the (un)covered parts of the code under test to find out root causes for the uncovered code. Our results show that JavaScript tests lack proper coverage for event-dependent callbacks (36%), asynchronous callbacks (53%), and DOM-related code (63%). We believe that it is worthwhile for the developer and research community to focus on testing techniques and tools to achieve better coverage for difficult to cover JavaScript code.","PeriodicalId":112258,"journal":{"name":"2017 IEEE International Conference on Software Testing, Verification and Validation (ICST)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114648229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abraham Chan, Stefan Winter, Habib Saissi, K. Pattabiraman, N. Suri
Error Propagation Analysis (EPA) is a technique forunderstanding how errors affect a program's execution and resultin program failures. For this purpose, EPA usually compares thetraces of a fault-free (golden) run with those from a faulty run ofthe program. This makes existing EPA approaches brittle for multithreadedprograms, which do not typically have a deterministicgolden run. In this paper, we study the use of likely invariantsgenerated by automated approaches as alternatives for goldenrun based EPA in multithreaded programs. We present InvariantPropagation Analysis (IPA), an approach and a framework forautomatically deriving invariants for multithreaded programs, and using the invariants for EPA. We evaluate the invariantsderived by IPA in terms of their coverage for different faulttypes across six representative programs through fault injectionexperiments. We find that stable invariants can be inferred in allsix programs, although their coverage of faults depends on theapplication and the fault type.
{"title":"IPA: Error Propagation Analysis of Multi-Threaded Programs Using Likely Invariants","authors":"Abraham Chan, Stefan Winter, Habib Saissi, K. Pattabiraman, N. Suri","doi":"10.1109/ICST.2017.24","DOIUrl":"https://doi.org/10.1109/ICST.2017.24","url":null,"abstract":"Error Propagation Analysis (EPA) is a technique forunderstanding how errors affect a program's execution and resultin program failures. For this purpose, EPA usually compares thetraces of a fault-free (golden) run with those from a faulty run ofthe program. This makes existing EPA approaches brittle for multithreadedprograms, which do not typically have a deterministicgolden run. In this paper, we study the use of likely invariantsgenerated by automated approaches as alternatives for goldenrun based EPA in multithreaded programs. We present InvariantPropagation Analysis (IPA), an approach and a framework forautomatically deriving invariants for multithreaded programs, and using the invariants for EPA. We evaluate the invariantsderived by IPA in terms of their coverage for different faulttypes across six representative programs through fault injectionexperiments. We find that stable invariants can be inferred in allsix programs, although their coverage of faults depends on theapplication and the fault type.","PeriodicalId":112258,"journal":{"name":"2017 IEEE International Conference on Software Testing, Verification and Validation (ICST)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117096141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cyrille Artho, Quentin Gros, Guillaume Rousset, Kazuaki Banzai, Lei Ma, Takashi Kitamura, M. Hagiya, Yoshinori Tanabe, M. Yamamoto
Apache ZooKeeper is a distributed data storage that is highly concurrent and asynchronous due to network communication, testing such a system is very challenging. Our solution using the tool "Modbat" generates test cases for concurrent client sessions, and processes results from synchronous and asynchronous callbacks. We use an embedded model checker to compute the test oracle for non-deterministic outcomes, the oracle model evolves dynamically with each new test step. Our work has detected multiple previously unknown defects in ZooKeeper. Finally, a thorough coverage evaluation of the core classes show how code and branch coverage strongly relate to feature coverage in the model, and hence modeling effort.
{"title":"Model-Based API Testing of Apache ZooKeeper","authors":"Cyrille Artho, Quentin Gros, Guillaume Rousset, Kazuaki Banzai, Lei Ma, Takashi Kitamura, M. Hagiya, Yoshinori Tanabe, M. Yamamoto","doi":"10.1109/ICST.2017.33","DOIUrl":"https://doi.org/10.1109/ICST.2017.33","url":null,"abstract":"Apache ZooKeeper is a distributed data storage that is highly concurrent and asynchronous due to network communication, testing such a system is very challenging. Our solution using the tool \"Modbat\" generates test cases for concurrent client sessions, and processes results from synchronous and asynchronous callbacks. We use an embedded model checker to compute the test oracle for non-deterministic outcomes, the oracle model evolves dynamically with each new test step. Our work has detected multiple previously unknown defects in ZooKeeper. Finally, a thorough coverage evaluation of the core classes show how code and branch coverage strongly relate to feature coverage in the model, and hence modeling effort.","PeriodicalId":112258,"journal":{"name":"2017 IEEE International Conference on Software Testing, Verification and Validation (ICST)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126825071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anurag Dwarakanath, Dipin Era, A. Priyadarshi, Neville Dubash, Sanjay Podder
Test automation involves the automatic execution of test scripts instead of being manually run. This significantly reduces the amount of manual effort needed and thus is of great interest to the software testing industry. There are two key problems in the existing tools & methods for test automation - a) Creating an automation test script is essentially a code development task, which most testers are not trained on, and b) the automation test script is seldom readable, making the task of maintenance an effort intensive process. We present the Accelerating Test Automation Platform (ATAP) which is aimed at making test automation accessible to non-programmers. ATAP allows the creation of an automation test script through a domain specific language based on English. The English-like test scripts are automatically converted to machine executable code using Selenium WebDriver. ATAP's English-like test script makes it easy for non-programmers to author. The functional flow of an ATAP script is easy to understand as well thus making maintenance simpler (you can understand the flow of the test script when you revisit it many months later). ATAP has been built around the Eclipse ecosystem and has been used in a real-life testing project. We present the details of the implementation of ATAP and the results from its usage in practice.
{"title":"Accelerating Test Automation through a Domain Specific Language","authors":"Anurag Dwarakanath, Dipin Era, A. Priyadarshi, Neville Dubash, Sanjay Podder","doi":"10.1109/ICST.2017.52","DOIUrl":"https://doi.org/10.1109/ICST.2017.52","url":null,"abstract":"Test automation involves the automatic execution of test scripts instead of being manually run. This significantly reduces the amount of manual effort needed and thus is of great interest to the software testing industry. There are two key problems in the existing tools & methods for test automation - a) Creating an automation test script is essentially a code development task, which most testers are not trained on, and b) the automation test script is seldom readable, making the task of maintenance an effort intensive process. We present the Accelerating Test Automation Platform (ATAP) which is aimed at making test automation accessible to non-programmers. ATAP allows the creation of an automation test script through a domain specific language based on English. The English-like test scripts are automatically converted to machine executable code using Selenium WebDriver. ATAP's English-like test script makes it easy for non-programmers to author. The functional flow of an ATAP script is easy to understand as well thus making maintenance simpler (you can understand the flow of the test script when you revisit it many months later). ATAP has been built around the Eclipse ecosystem and has been used in a real-life testing project. We present the details of the implementation of ATAP and the results from its usage in practice.","PeriodicalId":112258,"journal":{"name":"2017 IEEE International Conference on Software Testing, Verification and Validation (ICST)","volume":"207 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123222680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ricardo J. Dias, Carla Ferreira, Jan Fiedor, João M. Lourenço, A. Smrčka, Diogo Sousa, Tomáš Vojnar
The central notion of this paper is that of contracts for concurrency, allowing one to capture the expected atomicity of sequences of method or service calls in a concurrent program. The contracts may be either extracted automatically from the source code, or provided by developers of libraries or software modules to reflect their expected usage in a concurrent setting. We start by extending the so-far considered notion of contracts for concurrency in several ways, improving their expressiveness and enhancing their applicability in practice. Then, we propose two complementary analyses—a static and a dynamic one—to verify programs against the extended contracts. We have implemented both approaches and present promising experimental results from their application on various programs, including real-world ones where our approach unveiled previously unknown errors.
{"title":"Verifying Concurrent Programs Using Contracts","authors":"Ricardo J. Dias, Carla Ferreira, Jan Fiedor, João M. Lourenço, A. Smrčka, Diogo Sousa, Tomáš Vojnar","doi":"10.1109/ICST.2017.25","DOIUrl":"https://doi.org/10.1109/ICST.2017.25","url":null,"abstract":"The central notion of this paper is that of contracts for concurrency, allowing one to capture the expected atomicity of sequences of method or service calls in a concurrent program. The contracts may be either extracted automatically from the source code, or provided by developers of libraries or software modules to reflect their expected usage in a concurrent setting. We start by extending the so-far considered notion of contracts for concurrency in several ways, improving their expressiveness and enhancing their applicability in practice. Then, we propose two complementary analyses—a static and a dynamic one—to verify programs against the extended contracts. We have implemented both approaches and present promising experimental results from their application on various programs, including real-world ones where our approach unveiled previously unknown errors.","PeriodicalId":112258,"journal":{"name":"2017 IEEE International Conference on Software Testing, Verification and Validation (ICST)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129053746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
While directed model checking has proven to be a powerful tool in the fight against concurrency bugs, scalability remains a concern due to the combinatorial explosion in size of the state space. Overcoming that combinatorial explosion requires the selection and/or parameterization of meta*-heuristics, but we are left with a persistent problem of having to provide or compute specialized knowledge of the program under consideration, and this limits the practical value of the technique. To circumvent that, this paper investigates directed model checking as a platform for the synthesis of results from other analyses. We introduce an open-source tool, Ariadne, which translates reports of suspected race conditions of a static analyzer (Petablox) to instrumentation using a source-to-source compiler (ROSE) that can be exploited by a model checker (Java Pathfinder). We detail the algorithm used, present experimental results, and outline directions for future research.
{"title":"Ariadne: Hybridizing Directed Model Checking and Static Analysis","authors":"Reed Milewicz, P. Pirkelbauer","doi":"10.1109/ICST.2017.49","DOIUrl":"https://doi.org/10.1109/ICST.2017.49","url":null,"abstract":"While directed model checking has proven to be a powerful tool in the fight against concurrency bugs, scalability remains a concern due to the combinatorial explosion in size of the state space. Overcoming that combinatorial explosion requires the selection and/or parameterization of meta*-heuristics, but we are left with a persistent problem of having to provide or compute specialized knowledge of the program under consideration, and this limits the practical value of the technique. To circumvent that, this paper investigates directed model checking as a platform for the synthesis of results from other analyses. We introduce an open-source tool, Ariadne, which translates reports of suspected race conditions of a static analyzer (Petablox) to instrumentation using a source-to-source compiler (ROSE) that can be exploited by a model checker (Java Pathfinder). We detail the algorithm used, present experimental results, and outline directions for future research.","PeriodicalId":112258,"journal":{"name":"2017 IEEE International Conference on Software Testing, Verification and Validation (ICST)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127096497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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