title: Material UI OutlinedInput label is invisible
body: <p>We are using <a href="https://material-ui.com/api/outlined-input/" rel="noreferrer"><code>OutlinedInput</code></a> from Material UI, but text labels are not rendered. How to fix this?</p>
  <pre><code>import { Grid, OutlinedInput } from '@material-ui/core';
  </code></pre>
  <pre class="lang-xml prettyprint-override"><code>&lt;Grid container&gt;
    &lt;Grid item xs={12}&gt;
      &lt;OutlinedInput
        label=&quot;invisible label&quot;
        placeholder=&quot;HELLO, STACKOVERFLOW!&quot;
        value={value}
        onChange={(e) =&gt; handleValueChange(e.target.value)}
        fullWidth
      /&gt;
    &lt;/Grid&gt;
  &lt;/Grid&gt;
  </code></pre>
  <p>instead of expected &quot;invisible label&quot; text, an empty space is rendered (top left corner):</p>
  <p><a href="https://i.stack.imgur.com/aOKtJ.png" rel="noreferrer"><img src="https://i.stack.imgur.com/aOKtJ.png" alt="demo screenshot" /></a></p>