Yeeeh, you can pipe nothing because you don't want use any WriteableStream !!

Install it with npm or yarn.

With npm:
$ npm i pipenull

or

With yarn:
$ yarn add pipenull

Easy peasy !! like this one:

// Javascript
const pipenull = require("pipenull");
// Typescript
import pipenull from "pipenull";
...
.pipe(pipenull)
.on('end', ()=> {
    ....
});