Eclipse: green rectangle label on class

Question

What does the green thing displayed at the top right of the class icon mean?

I could not find anything on it after searching for the label inside the Eclipse preferences .

Answer 1

I never saw this, but very (dirty and very dangerous)) one could go to Window → Settings → General → Appearance → Shortcuts and at the same time select only one shortcut to see which pluggin this green window is doing, and then check this pluggin documentation.

Answer 2

Thanks to @ T.Des answer, I was able to find the answer:

It comes with a plugin I recently installed that greatly supports unit testing - MoreUnit