private MyMethodBuilder method(String name, String returnType, @Nullable String navigationClass) {
      MyMethodBuilder res = new MyMethodBuilder(myManager, name);
      res.setModifiers(GrModifierFlags.PUBLIC_MASK);
      res.setReturnType(type(returnType));
      res.setContainingClass(mySwingBuilderClass);
      if (navigationClass != null) {
        assert navigationClass.startsWith("groovy.swing."); // NON-NLS
        res.setNavigationClass(navigationClass);
      }
      return res;
    }
private MyMethodBuilder method(String name, String returnType, @Nullable String navigationClass)