private ExecutableElement objectMethod(String methodName) {
        TypeElement object = elements.getTypeElement(Object.class.getName());
        return methodsIn(object.getEnclosedElements()).stream()
            .filter(m -> m.getSimpleName().contentEquals(methodName))
            .findFirst()
            .orElseThrow(
                () ->
                    new IllegalArgumentException(
                        String.format("No method in Object named \"%s\"", methodName)));
      }
The overriding method that should be added to the subclass.
value/src/main/java/com/google/auto/value/extension/memoized/processor/MemoizeExtension.java