human
Solve the following python programming problem given the following code:
def _scan_tracks(self) : 
    def got_streams(streams, type_) : 
        if streams : 
            t = streams [0] 
            self._tracks.append ((t, type_)) 
d1 = self._sg.streams_by_params ({ 
        'type' : TYPE_AUDIO, 
}) 
    d1.addCallback (got_streams, chunks.MSG_AUDIO) 
    d2 = self._sg.streams_by_params ({ 
        'type' : TYPE_VIDEO, 
}) 
    d2.addCallback (self, chunks.MSG_VIDEO) 
    return defer.DeferredList ([d1, d2], fireOnOneErrback = 1, consumeErrors = 1) 

    
    

    Fix the buggy line: d2.addCallback (self, chunks.MSG_VIDEO)
assistant
#Here is Python program to fix the buggy line: d2.

d2.addCallback (got_streams, chunks.MSG_VIDEO)