code: def open_and_close_for_session(self, session_label):
          
          sched = self.schedule
  
          # `market_open` and `market_close` should be timezone aware, but pandas
          # 0.16.1 does not appear to support this:
          # http://pandas.pydata.org/pandas-docs/stable/whatsnew.html#datetime-with-tz  # noqa
          return (
              sched.at[session_label, 'market_open'].tz_localize(UTC),
              sched.at[session_label, 'market_close'].tz_localize(UTC),
          )
docs: 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.