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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def unique(seq):
 """ Returns a generator yielding unique sequence members in order A set by itself will return unique values without any regard for order. [1, 2, 3, 4] """

    seen = set()
    return (x for x in seq if x not in seen and not seen.add(x))