code: def find(self, query):
          '''Passes the query to the upstream, if it exists'''
          if self.upstream:
              return self.upstream.find(query)
          else:
              return Falsf find(self, query):
          '''Passes the query to the upstream, if it exists'''
          if self.upstream:
              return self.upstream.find(query)
          else:
              return False
docs: Passes the query to the upstream, if it exists