title: How to use helmet.js from typescript?
body: <p>It is pretty easy to use helmet from pure js per documentation:</p>
  
  <pre><code>const express = require('express')
  const helmet = require('helmet')
  
  const app = express()
  
  app.use(helmet())
  </code></pre>
  
  <p>But how can I use it from typescript? Typings file exports a bunch of stuff, one of which is helmet interface, which cannot be called as a function.. I can import it like this, but have no idea what to do next, what should I pass to app.use?</p>
  
  <pre><code>import * as helmet from 'helmet'
  </code></pre>
  
  <p>I have imported the latest version of both helmet and typings:</p>
  
  <pre><code>"@types/helmet": "0.0.43",
  "helmet": "^3.18.0"
  </code></pre>