export type GetPreconditionFn<T> = () => null | {
    value: T;
};
export type InitializerFn<I, T> = (precondition: I) => T | Promise<T>;
export interface AvailabilitySubscription {
    unsubscribe: () => void;
}
export interface Availability<T> {
    subscribe: (listener: (adapter: T) => void) => AvailabilitySubscription;
}
export declare function createAvailability<I, T>({ getPrecondition, initializer, pollIntervalMs, }: {
    getPrecondition: GetPreconditionFn<I>;
    initializer: InitializerFn<I, T>;
    pollIntervalMs?: number;
}): Availability<T>;