}
	meetPreconditions, err := meetPreconditions(patchMap, fns...)
	if err != nil {
		return nil, err
	}
	if !meetPreconditions {
		return nil, mergepatch.NewErrPreconditionFailed(patchMap)
	}

	return patch, nil
}

// keepOrDeleteNullInJsonPatch takes a json-encoded byte array and a boolean.
// It returns a filtered object and its corresponding json-encoded byte array.