Check if given appartment exists in the rumetr database

def check_appt(self, complex: str, house: str, appt: str) -> bool:
        """
        Check if given appartment exists in the rumetr database
        """
        self.check_house(complex, house)
        if '%s__%s__%s' % (complex, house, appt) in self._checked_appts:
            return True

        try:
            self.get('developers/{developer}/complexes/{complex}/houses/{house}/appts/{appt}'.format(
                developer=self.developer,
                complex=complex,
                house=house,
                appt=appt,
            ))
        except exceptions.Rumetr404Exception:
            raise exceptions.RumetrApptNotFound('Unknown appt (house is known) — may be you should create one?')

        self._checked_appts.add('%s__%s__%s' % (complex, house, appt))
        return True