code: def get_adjusted_value(
      self,
      asset,
      field,
      dt,
      perspective_dt,
      data_frequency,
      spot_value=None,
  ):
      # TODO: does this pertain to cryptocurrencies?
      log.warn("get_adjusted_value is not implemented yet!")
      return spot_value
  
imports: import abc
  import datetime
  import numpy
  import pandas
  from catalyst.assets._assets import TradingPair
  from catalyst.constants import LOG_LEVEL, AUTO_INGEST
  from catalyst.data.data_portal import DataPortal
  from catalyst.exchange.exchange_bundle import ExchangeBundle
  from catalyst.exchange.exchange_errors import ExchangeRequestError, PricingDataNotLoadedError
  from catalyst.exchange.utils.exchange_utils import resample_history_df, group_assets_by_exchange
  from catalyst.exchange.utils.datetime_utils import get_frequency, get_start_dt
  from logbook import Logger
  from redo import retry
label_desc: Use image node_id 8 for calling the DataPortalExchangeBase obj's underlying member method code with example usage: obj.get_adjusted_value(asset, field, dt, perspective_dt, data_frequency, spot_value) and returns: spot_value