code: def employee_id(self, employee_id):
          
  
          if employee_id is None:
              raise ValueError("Invalid value for `employee_id`, must not be `None`")
          if len(employee_id) < 1:
              raise ValueError("Invalid value for `employee_id`, length must be greater than or equal to `1`")
  
          self._employee_id = employee_id
docs: Sets the employee_id of this Shift.
          The ID of the employee this shift belongs to.
  
          :param employee_id: The employee_id of this Shift.
          :type: str