docs: def close(self):
          """Clean up (if no more connections to the db exist).
  
          * For in-memory: Delete the underlying SQL table from the
            in-memory database.
  
          * For on-disk: save and close connection
          """
  
          self.__decrement_connection_counter()
          if self.connection_count == 0:
              if self.dbfile == ":memory:":
                  SQL = """DROP TABLE IF EXISTS __self__"""
                  self.sql(SQL, asrecarray=False, cache=False)
              else:
                  self.connection.commit()
                  self.connection.close()