/**
 * Provides mechanism for blocking async processes and unblocking them from an external context.
 *
 * @template T The value that can be passed to {@link unblock} to resolve the {@link block} promise.
 */
export declare class Blocker<T = void> {
    private _promise?;
    private _unblock?;
    /**
     * `true` if {@link Blocker} is blocked and wasn't unblocked yet, or `false` otherwise.
     */
    get isBlocked(): boolean;
    /**
     * Returns promises that is fulfilled with the result passed to {@link unblock}. If blocker is already blocked
     * then the same promise is returned.
     */
    block(): Promise<T>;
    /**
     * Fulfills the promise returned from {@link block}. If the blocker isn't blocked then no-op.
     */
    unblock(value: T): void;
}