code: def get_available_currencies():
      
      r = requests.get(API_CURRENCIES)
      if r.status_code != requests.codes.ok:
          raise CryptonatorException(
              ("An error occurred while getting available currencies "
               "({} from Cryptonator).").format(r.status_code)
          )
  
      return [currency['code'] for currency in r.json()['rows']]
docs: Return a list of all available Cryptonator currencies.