Often, you can write your own implementation of a certain task or action. The class specification-editor enables you to specify and reference your own Java class.

The class specification-editor 

In the input field, you must enter the entire class name, including the indication of the Java packages (full qualified class name).
When you click the "J" button the following is examined:

1. 1. Whether the class is reachable over the class path,
   2. Whether it contains a default constructor, and
   3. Whether it implements the indicated Java interface.

If the class can be resolved, respectively instantiated, and the mentioned Java interface implemented, the light indicator changes from red to green. The text below input field talks about the Java interface, which must implement the specified class.