/**
 * 基类、单例
 */
export default class Provider {
    private static instance;

    private static readonly pool = {};

    constructor() {
    }

    public static getInstance<T extends typeof Provider>(this: T): InstanceType<T> {
        // return this.instance ||= new this();
        if (!this.instance) {
            this.instance = new this();
            Provider.pool[this.name] = this.instance;
        }
        return this.instance;
    }

    public static getPool() {
        return {
            pool: Provider.pool,
        }
    }
}