Takes a RBXScriptConnection, not the signal itself. connection object can be obtained from signal:Connect(fn) or getconnections(signal)[i].Most commonly used as a cheaper alternative to hookmetamethod - inspect what args a listener received instead of intercepting every game method.
In Doors, the server fires <RemoteEvent> RoomEvent whenever the player enters a new room. Grab the game’s own listener with getconnections and read what the server sent the next time it fires.
local args = getsignalarguments(workspace.ChildAdded)