Defines the functions implemented by Bovespa adapter
get_historical_file(year :: String.t()) :: {:ok, binary()} | {:error, :invalid_response}
get_historical_file(year :: String.t(), month :: String.t()) :: {:ok, binary()} | {:error, :invalid_response}
get_historical_file(year :: String.t(), month :: String.t(), day :: String.t()) :: {:ok, binary()} | {:error, :invalid_response}
get_item(code :: String.t()) :: {:ok, String.t()} | {:error, :invalid_response}
get_list() :: {:ok, String.t()} | {:error, :invalid_response}