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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 get_vads_trans_id(vads_site_id, vads_trans_date):
 """ Returns a default value for vads_trans_id field. vads_trans_id field is mandatory. It is composed by 6 numeric characters that identifies the transaction. There is a unicity contraint between vads_site_id and vads_trans_date (the first 8 characters representing the transaction date). We consider the probability of having 2 identical generated vads_trans_id in the same day as null."""

    vads_trans_id = ""
    for i in range(0, 6):
        vads_trans_id += str(random.randint(0, 9))
    return vads_trans_id