code: func keepOrDeleteNullInJsonPatch(patch []byte, keepNull bool) ([]byte, map[string]interface{}, error) {
  	var patchMap map[string]interface{}
  	err := json.Unmarshal(patch, &patchMap)
  	if err != nil {
  		return nil, nil, err
  	}
  	filteredMap, err := keepOrDeleteNullInObj(patchMap, keepNull)
  	if err != nil {
  		return nil, nil, err
  	}
  	o, err := json.Marshal(filteredMap)
  	return o, filteredMap, err
  }
docs: // keepOrDeleteNullInJsonPatch takes a json-encoded byte array and a boolean.
  // It returns a filtered object and its corresponding json-encoded byte array.
  // It is a wrapper of func keepOrDeleteNullInObj