A DESCRIPTION OF THE REQUEST :
When a class implements the Iterable<T> interface through other sub-interfaces, it may be that the class actually inherits multiple Iterable<T> signatures. The class might satisfy all of these signatures, but each Iterable has a different T which is strongly typed. The net result is that it is impossible to implement more than one kind of Iterable even when the type being iterated is a subtype of all the iterables which might be implemented.

JUSTIFICATION :
It is required for some cases of multiple interface inheritance.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Multiple interface inheritance should compile when all interface restrictions are met.
ACTUAL -
The code does not compile

---------- BEGIN SOURCE ----------
public interface Interface1
    extends Iterable<CharSequence>{ // this part fails

    public java.util.List<? extends CharSequence> getList(); // this part works.
}

public interface Interface2
    extends Iterable<Appendable>{ // this part fails

    public java.util.List<? extends Appendable> getList(); // this part works.
}


class NewClass implements Interface1, Interface2{
    private final List<StringBuffer> inner = new ArrayList<StringBuffer>();

    public List<StringBuffer> getList() { // compiles
        return inner;
    }
    
    public Iterator<StringBuffer> iterator() { // fails compile
        return inner.iterator();
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
A new interface must be written which inherits all top level interface, and passed as a parameterized argument to the sub-interfaces. The example above might look like this :

public interface Combined extends CharSequence, Appendable {}

public interface Interface1<T extends CharSequence extends Iterable<T>{
    public java.util.List<? extends CharSequence> getList(); // this part works.
}

public interface Interface2<T extends Appendable extends Iterable<T>{
    public java.util.List<? extends Appendable> getList(); // this part works.
}