(_.merge in ES6/ES7)Object.assign without overriding undefined values
<p>There is <a href="https://stackoverflow.com/questions/19965844/lodash-difference-between-extend-assign-and-merge?noredirect=1&amp;lq=1">_.merge</a> functionality in lodash. I want to achieve the same thing in ES6 or ES7.</p>

<p>Having this snippet:</p>

<pre><code>Object.assign({}, {key: 2}, {key: undefined})
</code></pre>

<p>I want to receive <code>{key: 2}</code>. Currently I receive <code>{key: undefined}</code></p>

<p>This is <strong>NOT</strong> a deep merge.</p>

<p>Is it possible? If yes then how to achieve that?</p>