def seq_arrival(self, seq_num):
        '''
        returns the packet in which the specified sequence number first arrived.
        '''
        try:
            return self.arrival_data.find_le(seq_num)[1]
        except __HOLE__:
            return None
dataset/ETHPy150Open andrewf/pcap2har/pcap2har/tcp/direction.py/Direction.seq_arrival