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