<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def waitForEvent(self, tv=0):
 """ See libusb_wait_for_event doc. """

        if tv is None:
            tv = 0
        tv_s = int(tv)
        real_tv = libusb1.timeval(tv_s, int((tv - tv_s) * 1000000))
        libusb1.libusb_wait_for_event(self.__context_p, byref(real_tv))