plugin-api
· Someone forgot to fill this in. See http://stackoverflow.com/questions/38272550/how-to-fail-the-gradle-build-if-subproject-is-missing-a-property
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 plugin-api-1.9.64.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.
