docstr: Retrieve current tick data for the given assets
  
  Parameters
  ----------
  assets: list[TradingPair]
  on_ticker_error: str [raise|warn]
      How to handle an error when retrieving a single ticker.
  
  Returns
  -------
  list[dict[str, float]
docstr_tok: ["Retrieve","current","tick","data","for","the","given","assets","Parameters","--","--","--","--","--","assets",":","list","[","TradingPair","]","on_ticker_error",":","str","[","raise|warn","]","How","to","handle","an","error","when","retrieving","a","single","ticker",".","Returns","--","--","--","-","list","[","dict","[","str",",","float","]"]
code: def tickers(self, assets, on_ticker_error="raise"):
      """
      Retrieve current tick data for the given assets
  
      Parameters
      ----------
      assets: list[TradingPair]
      on_ticker_error: str [raise|warn]
          How to handle an error when retrieving a single ticker.
  
      Returns
      -------
      list[dict[str, float]
  
      """
      pass
  
imports: import abc
  from abc import ABCMeta, abstractmethod, abstractproperty
  from datetime import timedelta
  from time import sleep
  import numpy
  import pandas
  from catalyst.constants import LOG_LEVEL
  from catalyst.data.data_portal import BASE_FIELDS
  from catalyst.exchange.exchange_bundle import ExchangeBundle
  from catalyst.exchange.exchange_errors import MismatchingQuoteCurrencies, SymbolNotFoundOnExchange, PricingDataNotLoadedError, NoDataAvailableOnExchange, NoValueForField, NoCandlesReceivedFromExchange, TickerNotFoundError, NotEnoughCashError
  from catalyst.exchange.utils.datetime_utils import get_delta, get_periods_range, get_periods, get_start_dt, get_frequency, get_candles_number_from_minutes
  from catalyst.exchange.utils.exchange_utils import get_exchange_symbols, resample_history_df, has_bundle, get_candles_df
  from logbook import Logger
label_desc: Use image node_id 29 for calling the Exchange obj's underlying member method code with example usage: obj.tickers(assets, on_ticker_error) without return types