* #2449 bump maven-checkstyle-plugin from 3.1.0 to 3.2.0 + resolve checkstyle issues
* remove FileSelectorJFrame.java to resolve checkstyle issue
* remove FileSelectorJFrame.java to resolve checkstyle issue
* remove FileSelectorJFrame.java to resolve checkstyle issue
* add refactored file with correct filename to resolve checkstyle issue
* add the test data
* change filenames from JFrame to Jframe for checkstyle
* fix code smell from sonar report
* add new testcases to improve the test coverage
* remove code smell
* Add custom license header style in order to comply with Google's Checkstyle format
* Update license headers to comply with Google's Checkstyle format
* 508 : Sonar qube critical Issue Fix
Refactor this method to reduce its Cognitive Complexity from 30 to the 15 allowed.
* 508: Sonar Qube Issue fxes
Define a constant instead of duplicating this literal " does not exist." 3 times.
* 508: sonar qube issue fixes
Define a constant instead of duplicating this literal "Some external api for only realtime execution could be called here." 3 times.