def _get_timespan(self, in_seconds=False):
if len(self):
timespan_ = self[0]._get_timespan(in_seconds=in_seconds)
start_offset = timespan_.start_offset
timespan_ = self[-1]._get_timespan(in_seconds=in_seconds)
stop_offset = timespan_.stop_offset
else:
start_offset = Duration(0)
stop_offset = Duration(0)
return Timespan(
start_offset=start_offset,
stop_offset=stop_offset,
)
