def basic_auth(credentials):
encoded = b64encode('<STR_LIT::>'.join(credentials).encode('<STR_LIT:ascii>')).decode()<EOL>return header_adder({'<STR_LIT>': '<STR_LIT>' + encoded})<EOL>
Create an HTTP basic authentication callable

    Parameters
    ----------
    credentials: ~typing.Tuple[str, str]
        The (username, password)-tuple

    Returns
    -------
    ~typing.Callable[[Request], Request]
        A callable which adds basic authentication to a :class:`Request`.