Why doesn't Java 5+ API take advantage of covariant return types?

Question

Since Java 5 we are allowed to have covariant return types. Why doesn\'t the Java API take advantage of this?

Take Graphics2D.create() for instance. Why

Answer 1

That would break binary compatibility. Previously compiled classes cannot find the method with the new return type. JLS3 §13.4.15, §13.4.12