Method onChange

packages/fsm/src/IStateMachine.ts:347–347

* @zh 监听任意状态变更 * @en Listen to any state change * * @param callback - @zh 回调函数 @en Callback function

(callback: StateChangeListener<TState>)

     * @param callback - @zh 回调函数 @en Callback function
     */
    onChange(callback: StateChangeListener<TState>): () => void;

    // =========================================================================
    // 调试 | Debug