Refactorings: extracting interfaces

You can create an interface that is based on the selected type. The Extract Interface dialog displays a list of methods and specifications that you can use to create new method specifications.

To create an interface, place the caret at a type, an interface, or a method that you want to use as a base for a new interface. Select Refactor | Extract | Interface. In the Extract Interface dialog, select members that you want to extract along with the interface and click Refactor.