From manual testing, we know this function works as expected. Testing…

… it in unit tests is non-trivial.

synapse/lib/cli.py

@@ -281,7 +281,7 @@ async def _onItemFini(self):
 
         await self.fini()
 
-    async def addSignalHandlers(self):
+    async def addSignalHandlers(self):  # pragma: no cover
         '''
         Register SIGINT signal handler with the ioloop to cancel the currently running cmdloop task.
         Removes the handler when the cli is fini'd.