code: def resolver(self):
          
          if self._resolver is None:
              self._resolver = RefResolver(self.base_uri, {})
          # if self.base_uri not in self._resolver.store:
          #    self._resolver.store[self.base_uri] = self.config
          return self._resolver
docs: Resolver for JSON Schema references. This can be based around a
          file or HTTP-based resolution base URI.