code: def drop(self, relation):
          
          dropped = _make_key(relation)
          logger.debug('Dropping relation: {!s}'.format(dropped))
          with self.lock:
              self._drop_cascade_relation(dropped)
docs: Drop the named relation and cascade it appropriately to all
          dependent relations.
  
          Because dbt proactively does many `drop relation if exist ... cascade`
          that are noops, nonexistent relation drops cause a debug log and no
          other actions.
  
          :param str schema: The schema of the relation to drop.
          :param str identifier: The identifier of the relation to drop.