docstr: Get currencies in which prices are quoted for the requested sids.
  
  Assumes that a sid's prices are always quoted in a single currency.
  
  Parameters
  ----------
  sids : np.array[int64]
      Array of sids for which currencies are needed.
  
  Returns
  -------
  currency_codes : np.array[object]
      Array of currency codes for listing currencies of
      ``sids``. Implementations should return None for sids whose
      currency is unknown.
code: def currency_codes(self, sids):
      """
      Get currencies in which prices are quoted for the requested sids.
  
      Assumes that a sid's prices are always quoted in a single currency.
  
      Parameters
      ----------
      sids : np.array[int64]
          Array of sids for which currencies are needed.
  
      Returns
      -------
      currency_codes : np.array[object]
          Array of currency codes for listing currencies of
          ``sids``. Implementations should return None for sids whose
          currency is unknown.
      """
  
file_path: zipline/zipline/data/session_bars.py
imports: from abc import abstractproperty, abstractmethod
  from zipline.data.bar_reader import BarReader
label_desc: Use image node_id 1 for calling the CurrencyAwareSessionBarReader obj's underlying member method code with example usage: obj.currency_codes(sids) without return types