aptana/studio3 — comment on commit 5d79dad8ac665b8dd584abb9e8eb537eef7a21c3
File: plugins/com.aptana.buildpath.core/src/com/aptana/core/build/AbstractBuildParticipant.java line 30
By sgtcoolguy:

The class doesn't re-define them as abstract, but it doesn't implement the buildFile and deleteFile methods from the interface, which is why it needs to be abstract.