docs: def _load_backend(self, backend_uri, context):
          """
          Return the instantiated backend object identified by the given
          `backend_uri`.
  
          The entry point that is used to create the backend object is determined
          by the protocol part of the given URI.
          """
          parsed = parse.urlparse(backend_uri)
          options = dict(parse.parse_qsl(parsed.query))
  
          try:
              backend = self._entry_points[self.BACKENDS_ENTRY_POINT][parsed.scheme].load()
          except KeyError:
              raise BackendNotFoundError(
                  "The requested backend `%s` could not be found in the "
                  "registered entry points. Perhaps you forgot to install the "
                  "corresponding backend package?" % parsed.scheme
              )
  
          password = (parse.unquote(parsed.password)
                      if parsed.password
                      else parsed.password)
  
          return backend(
              username=parsed.username, password=password,
              hostname=parsed.hostname, port=parsed.port,
              path=parsed.path, options=options, context=context,
          )