'Returns a tuple of timestamps of the open and close of the session
represented by the given label.
Parameters
session_label: pd.Timestamp
The session whose open and close are desired.
Returns
(Timestamp, Timestamp)
The open and close for the given session.'

def open_and_close_for_session(self, session_label):

    sched = self.schedule
    return (sched.at[(session_label, 'market_open')].tz_localize('UTC'), sched.at[(session_label, 'market_close')].tz_localize('UTC'))
