docs: def validate(self, value):
          """
          Return True if the choice is an integer; False otherwise.
  
          If the value was cast successfully to an int, set the choice that will
          make its way into the answers dict to the cast int value, not the
          string representation.
          """
          try:
              int_value = int(value)
              self._choice = int_value
              return True
          except ValueError:
              self.error_message = '%s is not a valid integer.' % value
              return False