import type { StateObserver } from "./types";
import type { StateEvent } from "../../storage/types";
import type { Transaction } from "../../storage/idb/Transaction";
import { BaseObservableValue } from "../../../observable/value";
/**
 * Observable value for a state event with a given type and state key.
 * Unsubscribes when last subscription is removed */
export declare class ObservedStateKeyValue extends BaseObservableValue<StateEvent | undefined> implements StateObserver {
    private readonly type;
    private readonly stateKey;
    private event?;
    private removeCallback?;
    constructor(type: string, stateKey: string);
    /** @internal */
    load(roomId: string, txn: Transaction): Promise<void>;
    /** @internal */
    handleStateEvent(event: StateEvent): void;
    get(): StateEvent | undefined;
    setRemoveCallback(callback: () => void): void;
    onUnsubscribeLast(): void;
}
export declare function tests(): Promise<{
    "test load and update": (assert: any) => Promise<void>;
}>;