code: def get_epoch():
      return pd.to_datetime("1970-1-1", utc=True)
  
file_path: catalyst/catalyst/exchange/utils/datetime_utils.py
imports: import calendar
  import math
  import re
  from datetime import datetime, timedelta, date
  import pandas
  import pytz
  from catalyst.exchange.exchange_errors import InvalidHistoryFrequencyError, InvalidHistoryFrequencyAlias
label_desc: Use image node_id 12 for calling a global function with example usage: get_epoch() and returns: pd