Developers choose open source packages from many alternatives. One increasingly important factor when choosing a package is its "social health", or a developer’s ability to get help on communication channels. We conduct a study to understand how developers learn about the social health of open source packages before using them. We offer preliminary results of the cues developers find.
{"title":"Social health cues developers use when choosing open source packages","authors":"Andrew Head","doi":"10.1145/2950290.2983973","DOIUrl":"https://doi.org/10.1145/2950290.2983973","url":null,"abstract":"Developers choose open source packages from many alternatives. One increasingly important factor when choosing a package is its \"social health\", or a developer’s ability to get help on communication channels. We conduct a study to understand how developers learn about the social health of open source packages before using them. We offer preliminary results of the cues developers find.","PeriodicalId":20532,"journal":{"name":"Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering","volume":"109 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76143803","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}
Bob Kurtz, P. Ammann, J. Offutt, M. Delamaro, M. Kurtz, N. Gökçe
Various forms of selective mutation testing have long been accepted as valid approximations to full mutation testing. This paper presents counterevidence to traditional selective mutation. The recent development of dominator mutants and minimal mutation analysis lets us analyze selective mutation without the noise introduced by the redundancy inherent in traditional mutation. We then exhaustively evaluate all small sets of mutation operators for the Proteum mutation system and determine dominator mutation scores and required work for each of these sets on an empirical test bed. The results show that all possible selective mutation approaches have poor dominator mutation scores on at least some of these programs. This suggests that to achieve high performance with respect to full mutation analysis, selective approaches will have to become more sophisticated, possibly by choosing mutants based on the specifics of the artifact under test, that is, specialized selective mutation.
{"title":"Analyzing the validity of selective mutation with dominator mutants","authors":"Bob Kurtz, P. Ammann, J. Offutt, M. Delamaro, M. Kurtz, N. Gökçe","doi":"10.1145/2950290.2950322","DOIUrl":"https://doi.org/10.1145/2950290.2950322","url":null,"abstract":"Various forms of selective mutation testing have long been accepted as valid approximations to full mutation testing. This paper presents counterevidence to traditional selective mutation. The recent development of dominator mutants and minimal mutation analysis lets us analyze selective mutation without the noise introduced by the redundancy inherent in traditional mutation. We then exhaustively evaluate all small sets of mutation operators for the Proteum mutation system and determine dominator mutation scores and required work for each of these sets on an empirical test bed. The results show that all possible selective mutation approaches have poor dominator mutation scores on at least some of these programs. This suggests that to achieve high performance with respect to full mutation analysis, selective approaches will have to become more sophisticated, possibly by choosing mutants based on the specifics of the artifact under test, that is, specialized selective mutation.","PeriodicalId":20532,"journal":{"name":"Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85287549","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}
Rapid UI responsiveness is a key consideration to Android app developers. However, the complicated concurrency model of Android makes it hard for developers to understand and further diagnose the UI performance. This paper presents DiagDroid, a tool specifically designed for Android UI performance diagnosis. The key notion of DiagDroid is that UI-triggered asynchronous executions contribute to the UI performance, and hence their performance and their runtime dependency should be properly captured to facilitate performance diagnosis. However, there are tremendous ways to start asynchronous executions, posing a great challenge to profiling such executions and their runtime dependency. To this end, we properly abstract five categories of asynchronous executions as the building basis. As a result, they can be tracked and profiled based on the specifics of each category with a dynamic instrumentation approach carefully tailored for Android. DiagDroid can then accordingly profile the asynchronous executions in a task granularity, equipping it with low-overhead and high compatibility merits. The tool is successfully applied in diagnosing 33 real-world open-source apps, and we find 14 of them contain 27 performance issues. It shows the effectiveness of our tool in Android UI performance diagnosis. The tool is open-source released online.
{"title":"DiagDroid: Android performance diagnosis via anatomizing asynchronous executions","authors":"Yu Kang, Yangfan Zhou, Hui Xu, Michael R. Lyu","doi":"10.1145/2950290.2950316","DOIUrl":"https://doi.org/10.1145/2950290.2950316","url":null,"abstract":"Rapid UI responsiveness is a key consideration to Android app developers. However, the complicated concurrency model of Android makes it hard for developers to understand and further diagnose the UI performance. This paper presents DiagDroid, a tool specifically designed for Android UI performance diagnosis. The key notion of DiagDroid is that UI-triggered asynchronous executions contribute to the UI performance, and hence their performance and their runtime dependency should be properly captured to facilitate performance diagnosis. However, there are tremendous ways to start asynchronous executions, posing a great challenge to profiling such executions and their runtime dependency. To this end, we properly abstract five categories of asynchronous executions as the building basis. As a result, they can be tracked and profiled based on the specifics of each category with a dynamic instrumentation approach carefully tailored for Android. DiagDroid can then accordingly profile the asynchronous executions in a task granularity, equipping it with low-overhead and high compatibility merits. The tool is successfully applied in diagnosing 33 real-world open-source apps, and we find 14 of them contain 27 performance issues. It shows the effectiveness of our tool in Android UI performance diagnosis. The tool is open-source released online.","PeriodicalId":20532,"journal":{"name":"Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81121168","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}
Diagnosis of performance problems is an essential part of software development and maintenance. This is in particular a challenging problem to be solved in the production environment where only program binaries are available with limited or zero knowledge of the source code. This problem is compounded by the integration with a significant number of third-party software in most large-scale applications. Existing approaches either require source code to embed manually constructed logic to identify performance problems or support a limited scope of applications with prior manual analysis. This paper proposes an automated approach to analyze application binaries and instrument the binary code transparently to inject and apply performance assertions on application transactions. Our evaluation with a set of large-scale application binaries without access to source code discovered 10 publicly known real world performance bugs automatically and shows that PerfGuard introduces very low overhead (less than 3% on Apache and MySQL server) to production systems.
{"title":"PerfGuard: binary-centric application performance monitoring in production environments","authors":"C. Kim, J. Rhee, K. H. Lee, X. Zhang, Dongyan Xu","doi":"10.1145/2950290.2950347","DOIUrl":"https://doi.org/10.1145/2950290.2950347","url":null,"abstract":"Diagnosis of performance problems is an essential part of software development and maintenance. This is in particular a challenging problem to be solved in the production environment where only program binaries are available with limited or zero knowledge of the source code. This problem is compounded by the integration with a significant number of third-party software in most large-scale applications. Existing approaches either require source code to embed manually constructed logic to identify performance problems or support a limited scope of applications with prior manual analysis. This paper proposes an automated approach to analyze application binaries and instrument the binary code transparently to inject and apply performance assertions on application transactions. Our evaluation with a set of large-scale application binaries without access to source code discovered 10 publicly known real world performance bugs automatically and shows that PerfGuard introduces very low overhead (less than 3% on Apache and MySQL server) to production systems.","PeriodicalId":20532,"journal":{"name":"Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering","volume":"485 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79974760","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. Sarma, M. Gerosa, Igor Steinmacher, Rafael Leano
Volunteers to Open Source Software (OSS) projects contribute not only to help creating software that they use, but also to gain skills and enrich their expertise and resumes. However, newcomers to OSS face several challenges when joining a project. Particularly, they do not know where to start, or choose tasks that they can be successful at. Here, we describe our vision towards BugExchange, a system that curates tasks from OSS projects and helps train newcomers. While evaluating and executing these tasks, newcomers can gain an understanding about the project, its technology, and concepts. There are many challenges in designing such a system. For example, identifying the information needs of newcomers, creating task recommendations that match newcomers’ skills and career goals, and providing mentoring and networking support. We plan to leverage our previous work to conceive and prototype our system, which will include multiple research lines. BugExchange has the potential to improve newcomer learning experiences, reduce dropouts, and foster community building.
{"title":"Training the future workforce through task curation in an OSS ecosystem","authors":"A. Sarma, M. Gerosa, Igor Steinmacher, Rafael Leano","doi":"10.1145/2950290.2983984","DOIUrl":"https://doi.org/10.1145/2950290.2983984","url":null,"abstract":"Volunteers to Open Source Software (OSS) projects contribute not only to help creating software that they use, but also to gain skills and enrich their expertise and resumes. However, newcomers to OSS face several challenges when joining a project. Particularly, they do not know where to start, or choose tasks that they can be successful at. Here, we describe our vision towards BugExchange, a system that curates tasks from OSS projects and helps train newcomers. While evaluating and executing these tasks, newcomers can gain an understanding about the project, its technology, and concepts. There are many challenges in designing such a system. For example, identifying the information needs of newcomers, creating task recommendations that match newcomers’ skills and career goals, and providing mentoring and networking support. We plan to leverage our previous work to conceive and prototype our system, which will include multiple research lines. BugExchange has the potential to improve newcomer learning experiences, reduce dropouts, and foster community building.","PeriodicalId":20532,"journal":{"name":"Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering","volume":"140 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88742296","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}
David Piorkowski, Austin Z. Henley, Tahmid Nabi, S. Fleming, Christopher Scaffidi, M. Burnett
Empirical studies have revealed that software developers spend 35%–50% of their time navigating through source code during development activities, yet fundamental questions remain: Are these percentages too high, or simply inherent in the nature of software development? Are there factors that somehow determine a lower bound on how effectively developers can navigate a given information space? Answering questions like these requires a theory that captures the core of developers' navigation decisions. Therefore, we use the central proposition of Information Foraging Theory to investigate developers' ability to predict the value and cost of their navigation decisions. Our results showed that over 50% of developers' navigation choices produced less value than they had predicted and nearly 40% cost more than they had predicted. We used those results to guide a literature analysis, to investigate the extent to which these challenges are met by current research efforts, revealing a new area of inquiry with a rich and crosscutting set of research challenges and open problems.
{"title":"Foraging and navigations, fundamentally: developers' predictions of value and cost","authors":"David Piorkowski, Austin Z. Henley, Tahmid Nabi, S. Fleming, Christopher Scaffidi, M. Burnett","doi":"10.1145/2950290.2950302","DOIUrl":"https://doi.org/10.1145/2950290.2950302","url":null,"abstract":"Empirical studies have revealed that software developers spend 35%–50% of their time navigating through source code during development activities, yet fundamental questions remain: Are these percentages too high, or simply inherent in the nature of software development? Are there factors that somehow determine a lower bound on how effectively developers can navigate a given information space? Answering questions like these requires a theory that captures the core of developers' navigation decisions. Therefore, we use the central proposition of Information Foraging Theory to investigate developers' ability to predict the value and cost of their navigation decisions. Our results showed that over 50% of developers' navigation choices produced less value than they had predicted and nearly 40% cost more than they had predicted. We used those results to guide a literature analysis, to investigate the extent to which these challenges are met by current research efforts, revealing a new area of inquiry with a rich and crosscutting set of research challenges and open problems.","PeriodicalId":20532,"journal":{"name":"Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering","volume":"s3-41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90831895","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}
We have developed and implemented a type system, the Signedness Type System, that captures usage of signed and unsigned integers in Java programs. This type system enables developers to detect errors regarding unsigned integers at compile time, and guarantees that such errors cannot occur at run time. In a case study. our type system proved easy to use and detected a previously unknown bug. Our type system is implemented as the Signedness Checker and will be available with the Checker Framework (http://CheckerFramework.org/).
{"title":"Preventing signedness errors in numerical computations in Java","authors":"Christopher A. Mackie","doi":"10.1145/2950290.2983978","DOIUrl":"https://doi.org/10.1145/2950290.2983978","url":null,"abstract":"We have developed and implemented a type system, the Signedness Type System, that captures usage of signed and unsigned integers in Java programs. This type system enables developers to detect errors regarding unsigned integers at compile time, and guarantees that such errors cannot occur at run time. In a case study. our type system proved easy to use and detected a previously unknown bug. Our type system is implemented as the Signedness Checker and will be available with the Checker Framework (http://CheckerFramework.org/).","PeriodicalId":20532,"journal":{"name":"Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering","volume":"500 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91449395","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}
JavaScript is one of the most popular programming languages. How- ever, understanding the dynamic behaviour of JavaScript apps is challenging in practice. There are many factors that hinder JavaScript comprehension, such as its dynamic, asynchronous, and event- driven nature, the dynamic interplay between JavaScript and the Document Object Model, and the asynchronous communication between client and server. In this research work, we have already proposed methods for understanding event-based and asynchronous JavaScript behaviour. To enhance the scalability of our methods, we propose a new technique that adopts bio-informatics algorithms to extract sequences of actions from execution traces that form higher-level patterns.
{"title":"Understanding behavioural patterns in JavaScript","authors":"Saba Alimadadi","doi":"10.1145/2950290.2983947","DOIUrl":"https://doi.org/10.1145/2950290.2983947","url":null,"abstract":"JavaScript is one of the most popular programming languages. How- ever, understanding the dynamic behaviour of JavaScript apps is challenging in practice. There are many factors that hinder JavaScript comprehension, such as its dynamic, asynchronous, and event- driven nature, the dynamic interplay between JavaScript and the Document Object Model, and the asynchronous communication between client and server. In this research work, we have already proposed methods for understanding event-based and asynchronous JavaScript behaviour. To enhance the scalability of our methods, we propose a new technique that adopts bio-informatics algorithms to extract sequences of actions from execution traces that form higher-level patterns.","PeriodicalId":20532,"journal":{"name":"Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering","volume":"9 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91452977","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}
Mahinthan Chandramohan, Yinxing Xue, Zhengzi Xu, Yang Liu, Chia Yuan Cho, Hee Beng Kuan Tan
Binary code search has received much attention recently due to its impactful applications, e.g., plagiarism detection, malware detection and software vulnerability auditing. However, developing an effective binary code search tool is challenging due to the gigantic syntax and structural differences in binaries resulted from different compilers, architectures and OSs. In this paper, we propose BINGO — a scalable and robust binary search engine supporting various architectures and OSs. The key contribution is a selective inlining technique to capture the complete function semantics by inlining relevant library and user-defined functions. In addition, architecture and OS neutral function filtering is proposed to dramatically reduce the irrelevant target functions. Besides, we introduce length variant partial traces to model binary functions in a program structure agnostic fashion. The experimental results show that BINGO can find semantic similar functions across architecture and OS boundaries, even with the presence of program structure distortion, in a scalable manner. Using BINGO, we also discovered a zero-day vulnerability in Adobe PDF Reader, a COTS binary.
近年来，二进制代码搜索因其在剽窃检测、恶意软件检测和软件漏洞审计等方面的重要应用而受到广泛关注。然而，开发一个有效的二进制代码搜索工具是具有挑战性的，因为不同的编译器、体系结构和操作系统导致二进制代码的巨大语法和结构差异。在本文中，我们提出了BINGO -一个可扩展和强大的二进制搜索引擎，支持各种架构和操作系统。关键的贡献是一种选择性内联技术，通过内联相关的库和用户定义函数来捕获完整的函数语义。此外，提出了结构和操作系统中立函数滤波，以显著减少不相关的目标函数。此外，我们还引入了长度变化的部分轨迹，以一种与程序结构无关的方式对二元函数进行建模。实验结果表明，即使存在程序结构失真，BINGO也能以可扩展的方式找到跨架构和操作系统边界的语义相似函数。使用BINGO，我们还在Adobe PDF Reader中发现了一个零日漏洞，这是一个COTS二进制文件。
{"title":"BinGo: cross-architecture cross-OS binary search","authors":"Mahinthan Chandramohan, Yinxing Xue, Zhengzi Xu, Yang Liu, Chia Yuan Cho, Hee Beng Kuan Tan","doi":"10.1145/2950290.2950350","DOIUrl":"https://doi.org/10.1145/2950290.2950350","url":null,"abstract":"Binary code search has received much attention recently due to its impactful applications, e.g., plagiarism detection, malware detection and software vulnerability auditing. However, developing an effective binary code search tool is challenging due to the gigantic syntax and structural differences in binaries resulted from different compilers, architectures and OSs. In this paper, we propose BINGO — a scalable and robust binary search engine supporting various architectures and OSs. The key contribution is a selective inlining technique to capture the complete function semantics by inlining relevant library and user-defined functions. In addition, architecture and OS neutral function filtering is proposed to dramatically reduce the irrelevant target functions. Besides, we introduce length variant partial traces to model binary functions in a program structure agnostic fashion. The experimental results show that BINGO can find semantic similar functions across architecture and OS boundaries, even with the presence of program structure distortion, in a scalable manner. Using BINGO, we also discovered a zero-day vulnerability in Adobe PDF Reader, a COTS binary.","PeriodicalId":20532,"journal":{"name":"Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87266325","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}
Static analysis is challenged by the dynamic language constructs of JavaScript which often lead to unacceptable performance and/or precision results. We describe an approach that focuses on improving the practicality and accuracy of points-to analysis and call graph construction for JavaScript programs. The approach first identifies program constructs which are sources of imprecision (i.e., root causes) through monitoring the static analysis process. We then examine and suggest specific context-sensitive analyses to apply. Our technique is able to to find that the root causes comprise less than 2% of the functions in JavaScript library applications. Moreover, the specialized analysis derived by our approach finishes within a few seconds, even on programs which can not complete within 10 minutes with the original analysis.
{"title":"Revamping JavaScript static analysis via localization and remediation of root causes of imprecision","authors":"Shiyi Wei, Omer Tripp, B. Ryder, Julian T Dolby","doi":"10.1145/2950290.2950338","DOIUrl":"https://doi.org/10.1145/2950290.2950338","url":null,"abstract":"Static analysis is challenged by the dynamic language constructs of JavaScript which often lead to unacceptable performance and/or precision results. We describe an approach that focuses on improving the practicality and accuracy of points-to analysis and call graph construction for JavaScript programs. The approach first identifies program constructs which are sources of imprecision (i.e., root causes) through monitoring the static analysis process. We then examine and suggest specific context-sensitive analyses to apply. Our technique is able to to find that the root causes comprise less than 2% of the functions in JavaScript library applications. Moreover, the specialized analysis derived by our approach finishes within a few seconds, even on programs which can not complete within 10 minutes with the original analysis.","PeriodicalId":20532,"journal":{"name":"Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79453136","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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