from_stop_id,to_stop_id,transfer_type,min_transfer_time
20001149,20001149,1,
20001489,20001768,0,
20001489,20001769,0,
20001768,20001489,0,
20001768,20002160,0,
20001769,20001489,0,
20001769,20002160,0,
20002160,20001768,0,
20002160,20001769,0,