peachy python test usb code

#!/usr/bin/python
import time
import os
import sys 

sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'src'))

from peachyprinter.infrastructure.communicator import UsbPacketCommunicator
from peachyprinter.infrastructure.messages import *


class TestCommunication(object):
    def __init__(self):
        self._usb = UsbPacketCommunicator(10)
        self._usb.register_handler(IAmMessage, self.i_am_handler)
        self._usb.start()
        self._usb.send(IdentifyMessage())
        time.sleep(0.1)
        self._usb.send(EnterBootloaderMessage())
        time.sleep(0.1)
        self._usb.close()

    def i_am_handler(self, message):
        print('Serial number: {0}'.format(message.sn))

if __name__ == '__main__':
    t = TestCommunication()