anchor.diff:  main() {
     defineReflectiveSuite(() {
       defineReflectiveTests(IndexTest);
  +    defineReflectiveTests(IndexWithNonFunctionTypeAliasesTest);
     });
   }
   
  
positive.code:       ..isUsed('x += 2;', IndexRelationKind.IS_READ_WRITTEN_BY)
        ..isUsed('x();', IndexRelationKind.IS_INVOKED_BY);
    }
  
    /// Asserts that [index] has an item with the expected properties.
    void _assertHasRelation(
  
negative.code:   }
  }
  
  class _NameIndexAssert {
    final IndexTest test;
    final String name;
  