docstr: Load a CSV from tests/resources/calendars/{filename}.csv
code: def load_answer_key(filename):
      """
      Load a CSV from tests/resources/calendars/{filename}.csv
      """
      fullpath = join(
          dirname(abspath(__file__)),
          "../resources",
          "calendars",
          filename + ".csv",
      )
  
      return read_csv(
          fullpath,
          index_col=0,
          # NOTE: Merely passing parse_dates=True doesn't cause pandas to set
          # the dtype correctly, and passing all reasonable inputs to the
          # dtype kwarg cause read_csv to barf.
          parse_dates=[0, 1, 2],
          date_parser=lambda x: pd.Timestamp(x, tz="UTC"),
      )
  
imports: from datetime import time
  from os.path import abspath, dirname, join
  from unittest import TestCase
  import numpy
  import pandas
  from nose_parameterized import parameterized
  from pandas import read_csv
  from pandas.tslib import Timedelta
  from pandas.util.testing import assert_index_equal
  from pytz import timezone
  from toolz import concat
  from catalyst.errors import CalendarNameCollision, InvalidCalendarName
  from catalyst.testing.predicates import assert_equal
  from catalyst.utils.calendars import deregister_calendar, get_calendar, register_calendar
  from catalyst.utils.calendars.calendar_utils import _default_calendar_aliases, _default_calendar_factories, register_calendar_type
  from catalyst.utils.calendars.trading_calendar import days_at_time, TradingCalendar
label_desc: Use image node_id 1 for calling the ExchangeCalendarTestBase obj's underlying member method code with example usage: obj.load_answer_key(filename) and returns: read_csv