/**



*/
/**
 * This package provides an abstract class for making objects Subscribable.
 *
 * @packageDocumentation
 */
/**
 * @ignore
 */
export declare type Unsubscribe = () => void;
/**
 * A basic class that can be subscribed to.
 */
export declare class Subscribable {
    /**
     * @ignore
     */
    protected __subscribers: Function[];
    /**
     * Adds a listener to the Subscribable object.
     *
     * ### Example
     *
     * ```ts
     * const unsubscribe = someSubscribable.add(() => {
     *   console.log("Update Received")
     * })
     *
     * setTimeout(unsubscribe, 5000)
     * ```
     *
     *
     * @param listener A function to be called when the `Subscribable` is updated.
     * @returns A function that will unsubscribe the listener.
     */
    subscribe(listener: Function): Unsubscribe;
    /**
     * Removes the given listener from the `Subscribable` object.
     *
     * @param listener The functioni to be removed.
     */
    unsubscribe(listener: Function): void;
    /**
     * Notifies subscribers that the `Subscribable` has changed.
     *
     * ### Example
     *
     * ```ts
     * class Cup extends Subscribable {
     *   isFull: boolean = false
     *
     *   fill() {
     *     this.isFull = true
     *     this.notifySubscribers()
     *   }
     *
     *   empty() {
     *     this.isFull = false
     *     this.notifySubscribers()
     *   }
     *
     * }
     *
     * const cup = new Cup()
     *
     * cup.subscribe(() => console.log(cup.isFull))
     *
     * cup.fill() // Logs: true
     * cup.empty() // Logs: false
     * ```
     */
    protected notifiySubscribers(): void;
}