/// <reference types="node" />
/// <reference types="node" />
import { Writable, WritableOptions } from "stream";
import { PopDataBuffer } from "../shared/PopDataBuffer";
export declare class PopServerStream extends Writable {
    readonly on_command: (data: string) => Promise<void>;
    protected _buffer: PopDataBuffer;
    /**
     * Constructs a new SMTP stream.
     * @param options the options.
     */
    constructor(options: WritableOptions, on_command: (data: string) => Promise<void>);
    /**
     * Handles a new chunk of data.
     * @param chunk the chunk of data.
     * @param encoding the encoding.
     * @param callback the callback.
     * @returns nothing.
     */
    _write(chunk: Buffer, encoding: BufferEncoding, next: (error?: Error | null) => void): Promise<void>;
    /**
     * Handles a command write.
     */
    protected _handle_command_write(): Promise<void>;
}