A DESCRIPTION OF THE REQUEST :
The method  handler should similar to Dot net delegate, a delegate is a class that can hold a reference to a method, so that the compiler can perform type checking for method definition, not class level.
so that it can very nice to support command pattern, at the same time, it also should provide best performance to dynamic invoke Java method.

JUSTIFICATION :
The method handler can provide more performance and nice type checking at compile time.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The method handler can refer to dot net delegate