code: def main_bundle_to_csv(self):
      exchange_name = "poloniex"
      data_frequency = "minute"
  
      exchange = get_exchange(exchange_name)
      asset = exchange.get_asset("eth_btc")
  
      start_dt = pd.to_datetime("2016-5-31", utc=True)
      end_dt = pd.to_datetime("2016-6-1", utc=True)
      self._bundle_to_csv(
          asset=asset,
          exchange_name=exchange.name,
          data_frequency=data_frequency,
          filename="{}_{}_{}".format(
              exchange_name, data_frequency, asset.symbol
          ),
          start_dt=start_dt,
          end_dt=end_dt,
      )
  
imports: import os
  import tempfile
  from logging import getLogger
  import pandas
  from catalyst.exchange.exchange_bcolz import BcolzExchangeBarReader, BcolzExchangeBarWriter
  from catalyst.exchange.exchange_bundle import ExchangeBundle, BUNDLE_NAME_TEMPLATE
  from catalyst.exchange.utils.bundle_utils import get_bcolz_chunk, get_df_from_arrays
  from catalyst.exchange.utils.datetime_utils import get_start_dt
  from catalyst.exchange.utils.exchange_utils import get_exchange_folder
  from catalyst.exchange.utils.factory import get_exchange
  from catalyst.exchange.utils.stats_utils import df_to_string
  from catalyst.utils.paths import ensure_directory
label_desc: Use image node_id 12 for calling the TestExchangeBundle obj's underlying member method code with example usage: obj.main_bundle_to_csv() without return types