Support empty senders in _do_dump instead.
@@ -140,6 +140,9 @@ def _do_dump(args):
if cycle_time is None:
cycle_time = '-'
+ if len(message.senders) == 0:
+ message.senders.append('-')
+
print()
print(' Name: {}'.format(message.name))
print(' Id: 0x{:x}'.format(message.frame_id))
