def METHOD_NAME(wn, tn):
    if tn is None:
        # special case. i.e. the last tile.
        #dont know why it is a special case, if the ALL-1 is received with a tile
        #then it should always be one, if the tile is consired received by the method
        #below, then it should not be false
        #i think the problem is when the sender does not know if it is the last one
        #so the the bitmap is received with the max_fcn bit on 1, but since there are
        #less tiles than the max_fcn. it does not look for that bit
        dprint("last tile case")
        #self.all_tiles[-1]["sent"] = False
        return
    # normal case.
    counter = 0
    dprint('unset_sent_flag_do')
    for t in self.all_tiles:
        if t["w-num"] == wn:
            if t["t-num"] == self.max_fcn - tn:
                counter += 1
                dprint('counter = {}, t-num {}, tn {}'.format(counter, t["t-num"],tn))
                t["sent"] = False
            elif t["t-num"] == self.max_fcn:
                dprint("t-num {} == max_fcn {}".format(t["t-num"],self.max_fcn))