allow empty event bus

Zsailer · Zsailer · commit 9d675ddb2a5d · 2022-04-30T17:47:32.000-07:00
diff --git a/jupyter_server/serverapp.py b/jupyter_server/serverapp.py
@@ -1534,6 +1534,7 @@ def _observe_contents_manager_class(self, change):
 
     event_bus = Instance(
         EventBus,
+        allow_none=True,
         help="An EventBus for emitting structured event data from Jupyter Server and extensions.",
     )
 

Original file line number	Diff line number	Diff line change
`@@ -1534,6 +1534,7 @@ def _observe_contents_manager_class(self, change):`
`1534`	`1534`
`1535`	`1535`	`event_bus = Instance(`
`1536`	`1536`	`EventBus,`
	`1537`	`+ allow_none=True,`
`1537`	`1538`	`help="An EventBus for emitting structured event data from Jupyter Server and extensions.",`
`1538`	`1539`	`)`
`1539`	`1540`