Creates the state address for a given setting key.

def _key_to_address(key):
    """Creates the state address for a given setting key.
    """
    key_parts = key.split('.', maxsplit=_MAX_KEY_PARTS - 1)
    key_parts.extend([''] * (_MAX_KEY_PARTS - len(key_parts)))

    return SETTINGS_NAMESPACE + ''.join(_short_hash(x) for x in key_parts)