Identify the source of "source-group-complete"

There are different ways to load a media into the rv

  1. From the terminal, using rv
  2. Drag and drop from shotgun ui
    3 Using rv commands(commands .addSource)

Is there a way to differentiate which of the above means triggered the source-group-complete event

def check_for_shotgun_info(self, event):

        # is there any attribute in the event that recognise the means of trigger
        # the current attributes didn't help
        print("%s %s %s" % (event.contents(), event.sender(), ))