code: private static int getMethodModifiers(ExecutableElement method) {
      int modifiers = ElementUtil.fromModifierSet(method.getModifiers());
      if (method.isVarArgs()) {
        modifiers |= ElementUtil.ACC_VARARGS;
      }
      if (ElementUtil.isSynthetic(method)) {
        modifiers |= ElementUtil.ACC_SYNTHETIC;
      }
      return modifiers;
    }
docs: Returns the modifiers for a specified method, including internal ones.
  All method modifiers are defined in the JVM specification, table 4.5.