One more attempt at pre-commit checks

Author: kevin-bates

jupyter_server/gateway/gateway_client.py

@@ -18,7 +18,6 @@
 from jupyter_events import EventLogger
 from tornado import web
 from tornado.httpclient import AsyncHTTPClient, HTTPClientError, HTTPResponse
-from tornado.httputil import HTTPHeaders
 from traitlets import (
     Bool,
     Float,
@@ -35,6 +34,9 @@
 
 from jupyter_server import DEFAULT_EVENTS_SCHEMA_PATH, JUPYTER_SERVER_EVENTS_URI
 
+if ty.TYPE_CHECKING:
+    from tornado.httputil import HTTPHeaders
+
 ERROR_STATUS = "error"
 SUCCESS_STATUS = "success"
 STATUS_KEY = "status"