code: func (mock *Mock) GetFileNames(paths []string) ([]string, error) {
  	items := mock.getReturnValues("GetFileNames")
  	if len(items) == 1 {
  		switch typed := items[0].(type) {
  		case []string:
  			return typed, nil
  		case error:
  			return []string{}, typed
  		}
  	} else if len(items) == 2 {
  		return items[0].([]string), items[1].(error)
  	}
  	return []string{}, nil
  }
docs: // GetFileNames mocks original method