'Read the length of the sync marker; if it matches the sync marker,
return True. Otherwise, seek back to where we started and return False.'

def _skip_sync(self):

    proposed_sync_marker = self.reader.read(SYNC_SIZE)
    if (proposed_sync_marker != self.sync_marker):
        self.reader.seek((- SYNC_SIZE), 1)
        return False
    else:
        return True
