<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def ordered_uniqify(sequence):
 """ Uniqifies the given hashable sequence while preserving its order. :param sequence: Sequence. :type sequence: object :return: Uniqified sequence. :rtype: list """


    items = set()
    return [key for key in sequence if key not in items and not items.add(key)]