def get_database(self, instance_id, database_id, project_id=None):
        """
        
        """

        instance = self._get_client(project_id=project_id).instance(
            instance_id=instance_id)
        if not instance.exists():
            raise AirflowException("The instance {} does not exist in project {} !".
                                   format(instance_id, project_id))
        database = instance.database(database_id=database_id)
        if not database.exists():
            return None
        else:
            return database