def _getargs(fn_sig):
    """
    Returns list of positional and keyword argument names in order.
    """
    params = fn_sig.parameters
    args = []
    for k, v in params.items():
        if (v.kind & v.POSITIONAL_OR_KEYWORD) == v.POSITIONAL_OR_KEYWORD:
            args.append(k)
        else:
            msg = "%s argument type unsupported in jitclass" % v.kind
            raise errors.UnsupportedError(msg)
    return args

    Returns list of positional and keyword argument names in order.
    
numba/experimental/jitclass/base.py