docs: def _logic(self, value=None):
          # type: (Any) -> Tuple[Union[bool, None], str]
          """Process the inner logic of the validator.
  
          The validation results are returned as tuple (boolean (true/false), reasontext)
          """
          self._validation_result, self._validation_reason = None, 'No reason'
          return self._validation_result, self._validation_reason