title: Import file in webpack only if file exists in ES6 syntax
body: <p>Basically, I need to get variable from file, otherwise to get variable from default file.</p>
  <p>I see best solution as:</p>
  <pre><code>import { variable } from &quot;file.js&quot;; // if variable exists
  import { variable } from &quot;default.js&quot;; // otherwise import variable from default
  </code></pre>
  <p>But if file.js not exists I get an error. And its expecting, but not needs for me in this case. <strong>Is it possible to fix it with webpack and just ignore this import if file not exists?</strong></p>
  <p>An <code>import()</code> statement isn't fit because I need import on build stage, not dynamic import at runtime.</p>