code: def database(self):
          
          #1. Initialize
          self.callback.im_self.db = sql.setup(self.settings)
          if self.callback.im_self.db:
              module = '.'.join(self.callback.im_self.__module__.split('.')[:-1])
              sql.init(module, self.callback.im_self.db)
              self.callback.im_self.db.connect()
          yield
          #2. Cleanup
          if self.callback.im_self.db:
              self.callback.im_self.db.close()
docs: Before the callback is called, initialize the database if needed.
          :rtype: None