code: def fetch(
          self, request: Union["HTTPRequest", str], **kwargs: Any
      ) -> "HTTPResponse":
          
          response = self._io_loop.run_sync(
              functools.partial(self._async_client.fetch, request, **kwargs)
          )
          return response
docs: Executes a request, returning an `HTTPResponse`.
  
          The request may be either a string URL or an `HTTPRequest` object.
          If it is a string, we construct an `HTTPRequest` using any additional
          kwargs: ``HTTPRequest(request, **kwargs)``
  
          If an error occurs during the fetch, we raise an `HTTPError` unless
          the ``raise_error`` keyword argument is set to False.