/**
 * Creates an appendable stream that allows multiple ReadableStreams to be
 * appended sequentially. The streams are processed one after another, and
 * all data is forwarded to a single output ReadableStream.
 *
 * This is useful when you need to combine multiple streams that arrive
 * asynchronously into a single continuous stream.
 */
export declare function createAppendableStream<T>(): {
    output: ReadableStream<any>;
    append: (readable: ReadableStream<T>) => Promise<void>;
    finalize: () => Promise<void>;
};
