The Extract Superclass refactoring allows you to extract certain members from a selected class into a new base class. The original class will be inherited from the created base class.
To extract a superclass:
Place a caret at a class name or any place within a class.
Selecton the main menu.
In the Extract Superclass dialog, specify the superclass name, a directory where it should be placed, and select members to be added:
Click OK. RubyMine will create a superclass in a separate file.