'Start the timeout clock, used during a connect() attempt
:raises urllib3.exceptions.TimeoutStateError: if you attempt
to start a timer that has been started already.'

def start_connect(self):

    if (self._start_connect is not None):
        raise TimeoutStateError('Timeout    timer    has    already    been    started.')
    self._start_connect = current_time()
    return self._start_connect
