A testing framework for developing unit tests that required
a JCR repository. The framework contains mock repositories, assertion
and other helper classes.
Download JD-GUI to open JAR file and explore Java source code file (.class .java)
Click menu "File → Open File..." or just drag-and-drop the JAR file in the JD-GUI window parent-0.4.8.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.