Process the inner logic of the validator.

        The validation results are returned as tuple (boolean (true/false), reasontext)

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