anchor.diff:      if (!isImplicitCall) {
         interfaceMember = _getRealTarget(interfaceMember);
         _replaceReference(interfaceMember);
  -      _replaceType(calleeType);
  +      _replaceType(const NullType()); // callee type
       }
       super.genericExpressionExit("methodInvocation", expression, inferredType);
     }
  
positive.code: 
      if (!isImplicitCall) {
        _replaceReference(const NullNode('explicit-call'));
        _replaceType(const NullType());
      }
      super.genericExpressionExit("methodInvocation", expression, inferredType);
    }
  
negative.code:         ? calleeType
          : substitution.substituteType(calleeType.withoutTypeParameters);
      _replaceType(invokeType);
      _replaceType(const NullType()); // callee type
      super.genericExpressionExit("staticInvocation", expression, inferredType);
    }
  
  