Interrupts the current database from processing.

def interrupt(self):
        """
        Interrupts the current database from processing.
        """
        if self._database and self._databaseThreadId:
            # support Orb 2 interruption capabilities
            try:
                self._database.interrupt(self._databaseThreadId)
            except AttributeError:
                pass
        
        self._database = None
        self._databaseThreadId = 0