def not_none(**kwargs):
    """Confirms that at least one of the items is not None.

    Parameters
    ----------
    **kwargs : dict of any, optional
        Items of arbitrary type.

    Returns
    -------
    dict of any
        Items that are not None.

    Raises
    -------
    ValueError
        If all of the items are None.
    """
    valid_items = {}
    all_none = True
    for key, value in kwargs.items():
        if value is not None:
            all_none = False
            valid_items[key] = value
    if all_none:
        raise ValueError('At least one of {{{}}} should be not None!'.format(
            ', '.join(kwargs)))

    return valid_items