whole_func_string: function errorMessage(state = null, action) {
    const { type, error } = action
  
    if (type === ActionTypes.RESET_ERROR_MESSAGE) {
      return null
    } else if (error) {
      return action.error
    }
  
    return state
  }
func_code_string: function errorMessage(state = null, action) {
    const { type, error } = action
  
    if (type === ActionTypes.RESET_ERROR_MESSAGE) {
      return null
    } else if (error) {
      return action.error
    }
  
    return state
  }
func_documentation_string: Updates error message to notify about the failed fetches.