Let's create a folder called big-file-server, with an index.js.

We'll need to initialize the folder as a package, install the pump module, and create and index.js file:

$ mkdir big-file-server 
$ cd big-file-server 
$ npm init -y  
$ npm install --save pump 
$ touch index.js 

We'll also need a big file, so let's create that quickly:

$ node -e "process.stdout.write(crypto.randomBytes(1e9))" > big.file