function createHarness( options, clbk ) {
	var cb;

	if ( arguments.length === 0 ) {
		cb = noop;
	} else if ( arguments.length === 1 ) {
		if ( isFunction( options ) ) {
			cb = options;
		} else {
			cb = noop;
		}
	} else {
		cb = clbk;
	}
	/**
	* Mock harness.
	*
	* @private
	*/
	function harness() {
		// No-op...
	}

	/**
	* Mock create stream.
	*
	* @private
	* @param {Options} [opts] - options
	* @returns {TransformStream} transform stream
	*/
	function createStream( opts ) {
		if ( arguments.length ) {
			return new TransformStream( opts );
		}
		return new TransformStream();
	}

	/**
	* Mock close.
	*
	* @private
	*/
	function closeHarness() {
		// No-op...
	}

	/**
	* Mock exit.
	*
	* @private
	*/
	function exit() {
		// No-op...
	}

	/**
	* Provides a hook for mock consumers to "end" a harness.
	*
	* @private
	*/
	function end() {
		setTimeout( onTimeout, 0 );
	}

	/**
	* Callback invoked upon a timeout.
	*
	* @private
	*/
	function onTimeout() {
		cb();
	}

	harness.createStream = createStream;
	harness.close = closeHarness;
	harness.exit = exit;
	harness.end = end;
	harness.exitCode = 0;

	return harness;
}
Mock harness.

@private
@param {Options} options - options
@param {Callback} clbk - callback
@returns {Function} harness