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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 _merge(listA, listB):
 """ Merges two list of objects removing repetitions. """

    listA = [x.id for x in listA]
    listB = [x.id for x in listB]
    listA.extend(listB)
    set_ = set(listA)
    return list(set_)