A lot of code coverage utilities that exist today share a common dtd format for coverage results. We noticed that similar code was being written for the cobertura, jacoco and a few other plugins. This caused us to develop the code coverage api plugin which shares common apis for coverage results.
A lot of work needed to be done to remove duplicate code and provide similarity across all plugins. This also required major changes to both the jacoco and cobertura plugins which were seen with very positive results.
This project was very transparent to the open source Jenkins community. You can find the final results of the plugin: https://www.jenkins.io/projects/gsoc/2018/code-coverage-api-plugin/. The plugin is also available for download: https://github.com/jenkinsci/code-coverage-api-plugin