def keep_arg(i, arg_name, typ):
    """
    Return whether `arg_name` should be included in the type annotation.

    Parameters
    ----------
    i : int
        position within the arg list

    arg_name : str
    typ : Optional[str]
        type of the arg

    Returns
    -------
    bool
    """
    return not (i == 0 and arg_name in {'self', 'cls'} and typ is None)
