export declare class PrivateDocumentStorage {
    private readonly root;
    private readonly docDir;
    constructor(root?: string);
    save(extension: string, body: Buffer): Promise<string>;
    read(filename: string): Promise<Buffer>;
    exists(filename: string): Promise<boolean>;
    delete(filename: string): Promise<void>;
    private absPath;
}
export declare function resolvePrivateUploadsRoot(localDir?: string): string;