title: Duplicate Button Baseline from Material UI in header
body: <ul>
  <li>@material-ui/core - 4.3.1</li>
  <li>react - 16.8.6/16.9.0</li>
  <li>webpack - 4.38.0/4.39.1</li>
  </ul>
  
  <p>In our project when we have a material ui button in one component, then in a separate component on the same page we use an expansion panel or another type of button we have a second instance of MuiButtonBase imported into the header. This is causing our custom styles to be overwritten and styles to be dumped all together. </p>
  
  <p>We've followed the steps from <a href="https://material-ui.com/getting-started/faq/#i-have-several-instances-of-styles-on-the-page" rel="nofollow noreferrer">https://material-ui.com/getting-started/faq/#i-have-several-instances-of-styles-on-the-page</a></p>
  
  <p>We've also tried the steps found on <a href="https://github.com/mui-org/material-ui/issues/15610" rel="nofollow noreferrer">https://github.com/mui-org/material-ui/issues/15610</a></p>
  
  <p>Neither of these has fixed this for us. :( </p>
  
  <pre><code> splitChunks: {
        chunks: 'async',
        minChunks: 2,
        name: 'vendor',
        cacheGroups: {
          vendor: {
            test: /[\\/]node_modules[\\/]/,
            priority: -10,
          },
        }
      },
    },
  </code></pre>
  
  <pre><code>import {
    Modal, Button,
  } from '@material-ui/core';
  
  () =&gt; (
    &lt;Modal open={open}&gt;
            &lt;Button className={classes.cancel} onClick={onCancel}&gt;{cancelText}&lt;/Button&gt;
            &lt;Button className={classes.delete} onClick={onConfirm}&gt;{confirmText}&lt;/Button&gt;
    &lt;/Modal&gt;
  );
  </code></pre>
  
  <pre><code>import {
    ExpansionPanel, ExpansionPanelSummary, ExpansionPanelDetails,
  } from '@material-ui/core';
  
  () =&gt; (
  &lt;ExpansionPanel expanded={expanded}&gt;
          &lt;ExpansionPanelSummary onClick={toggle} className={classes.summary} expandIcon={&lt;ExpandMore /&gt;}&gt;
            &lt;span&gt;
              {name}
            &lt;/span&gt;
          &lt;/ExpansionPanelSummary&gt;
          &lt;ExpansionPanelDetails&gt;
            {children}
          &lt;/ExpansionPanelDetails&gt;
        &lt;/ExpansionPanel&gt;
  );
  </code></pre>
  
  <p>It'd be great if we didn't have two MuiButtonBases causing our styles to be overridden.</p>
  
  <p><img src="https://i.imgur.com/lM29xo6.png" alt="Image"></p>