def kwonly_args(kws, required, withdefaults=(), leftovers=False):
    """
    Based on the snippet by Eric Snow
    http://code.activestate.com/recipes/577940

    SPDX-License-Identifier: MIT
    """

    if hasattr(withdefaults, 'items'):
        # allows for OrderedDict to be passed
        withdefaults = withdefaults.items()

    kwonly = []

    # extract the required keyword-only arguments
    missing = []
    for name in required:
        if name not in kws:
            missing.append(name)
        else:
            kwonly.append(kws.pop(name))

    # validate required keyword-only arguments
    if missing:
        if len(missing) > 2:
            end = 's: %s, and %s' % (', '.join(missing[:-1]), missing[-1])
        elif len(missing) == 2:
            end = 's: %s and %s' % tuple(missing)
        else:
            end = ': %s' % tuple(missing)

        msg = 'missing %s required keyword-only argument%s'
        raise TypeError(msg % (len(missing), end))

    # handle the withdefaults
    for name, value in withdefaults:
        if name not in kws:
            kwonly.append(value)
        else:
            kwonly.append(kws.pop(name))

    # handle any leftovers
    if not leftovers and kws:
        msg = "got an unexpected keyword argument '%s'"
        raise TypeError(msg % (next(iter(kws.keys()))))

    return [kws] + kwonly