- TestBatcher_CloseBeforeStart_DoesNotHang: verifies Close() before
Start() returns promptly now that done is initialized in NewBatcher.
- TestBatcher_QueueWorkAfterClose_DoesNotHang: verifies queueWork
returns via the done channel after Close(), even without Start().
- TestIsConnected_FalseAfterAddNodeFailure: verifies IsConnected
returns false after AddNode fails and removes the last connection.
- TestRemoveConnectionAtIndex_NilsTrailingSlot: verifies the backing
array slot is nil-ed after removal to avoid retaining pointers.
Updates #2545