Create a timer for the client driver to watch for events
    
    @param client_id: ID of clinet user

def init_timer(client_id):
    """Create a timer for the client driver to watch for events
    
    @param client_id: ID of clinet user
    """
    if client_id in timers and timers[client_id]:
        timers[client_id].start()
        return
    # Create a timer to call check_new_message function after every 2 seconds.
    # client_id param is needed to be passed to check_new_message
    timers[client_id] = RepeatedTimer(2, check_new_messages, client_id)