def METHOD_NAME(packets, plot):
    first_send_time_diff = (packets[0].arrival_timestamp -
                            packets[0].send_timestamp)
    y = [(packet.arrival_timestamp - packet.send_timestamp) -
         first_send_time_diff for packet in packets]
    plot.grid(True)
    plot.set_title("SendTime difference [us]")
    plot.plot(GetTimeAxis(packets), y)