code: def __init__(self, *args, **kwargs):
      super(OpenExchangeCalendar, self).__init__(
          start=Timestamp("2015-3-1", tz="UTC"), **kwargs
      )
  
file_path: catalyst/catalyst/utils/calendars/exchange_calendar_open.py
imports: from datetime import time
  from pytz import timezone
  from pandas import Timestamp
  from pandas.tseries.offsets import DateOffset
  from catalyst.utils.memoize import lazyval
  from .trading_calendar import TradingCalendar
label_desc: Use image node_id 6 to create a new OpenExchangeCalendar object from inherited base classes: TradingCalendar with example: obj = OpenExchangeCalendar()