<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _decode(data):
 """Decode the base-64 encoded string :param data: :return: decoded data """

    if not isinstance(data, bytes_types):
        data = six.b(str(data))
    return base64.b64decode(data.decode("utf-8"))