'Returns the last data value for this key, or [] if it\'s an empty list;
raises KeyError if not found.'

def __getitem__(self, key):

    try:
        list_ = super(MultiValueDict, self).__getitem__(key)
    except KeyError:
        raise MultiValueDictKeyError(repr(key))
    try:
        return list_[(-1)]
    except IndexError:
        return []
