'Start the connection up'

def start(self):

    if self.connection_closed.is_set():
        (self._read_pipe, self._write_pipe) = create_pipe()
        self.connection_closed.clear()
    if self._connection_routine:
        raise Exception('Unable    to    start,    connection    routine    already    active.')
    self._connection_routine = self.handler.spawn(self.zk_loop)
