Convert a GTFS 'frequencies' table to equivalent 'stop_times' that can be used for routing.
frequencies_to_stop_times(gtfs)A set of GTFS data returned from extract_gtfs.
The input GTFS data with data from the 'frequencies' table converted
to equivalent 'arrival_time' and 'departure_time' values in stop_times.
Other augment:
gtfs_transfer_table()