export declare class UnshiftableStream {
    buffer: Uint8Array;
    reader: ReadableStreamDefaultReader<Uint8Array>;
    readable: ReadableStream<Uint8Array>;
    paused?: PromiseWithResolvers<void>;
    constructor(sourceStream: ReadableStream<Uint8Array>);
    unshift: (data: Uint8Array) => void;
    pause(): void;
    resume(): void;
    read(): Promise<ReadableStreamReadDoneResult<Uint8Array> | {
        done: boolean;
        value: Uint8Array;
    }>;
}