Why declare an interface as abstract?

Question

What's point of declaring an interface as abstract? Same thing for an interface method. Is there a point to it?

eg.

public abstract interface Presenter {  public abstract void go(final HasWidgets container); } 

Answer 1

Where did you come across the chunk of code you have posted, any old java code base ?
This is what the JLS has to say :

9.1.1.1 abstract Interfaces:
Every interface is implicitly abstract. This modifier is obsolete and should not be used in new programs.

9.4 Abstract Method Declarations:
For compatibility with older versions of the Java platform, it is permitted but discouraged, as a matter of style, to redundantly specify the abstract modifier for methods declared in interfaces.

Answer 2

Interfaces and interface methods are implicitly abstract even if not declared as so. So there is no need to explicitly specify it.