def read_records(self, file_name, range_tracker):
    records = super(_TextSourceWithFilename, self).read_records(file_name, range_tracker)
    for record in records:
        (yield (file_name, record))
def read_records(self, file_name, range_tracker):
    records = super(_TextSourceWithFilename, self).read_records(file_name, range_tracker)
    for record in records:
        (yield (file_name, record))