title: Material-UI React TypeScript Component Styles Error w/ Default Theme
body: <p>I'm integrating Material-UI (v4.4.3) into a React (v16.9.2) TypeScript (v3.6.3) website. Using the sample AppBar component example <a href="https://material-ui.com/components/app-bar/" rel="nofollow noreferrer">https://material-ui.com/components/app-bar/</a> and the TypeScript Guide <a href="https://material-ui.com/guides/typescript/#typescript" rel="nofollow noreferrer">https://material-ui.com/guides/typescript/#typescript</a> I have the following functional component.</p>
  
  <p>However, I'm getting a TS error for <em>useStyles()</em> on this line</p>
  
  <pre><code>const classes = useStyles();
  </code></pre>
  
  <p><em>(TS): Expected one argument, but got 0.</em></p>
  
  <pre><code>import * as React from 'react';
  
  import { createStyles, Theme, makeStyles } from '@material-ui/core/styles';
  import AppBar from '@material-ui/core/AppBar';
  import Toolbar from '@material-ui/core/Toolbar';
  import Typography from '@material-ui/core/Typography';
  import Button from '@material-ui/core/Button';
  import IconButton from '@material-ui/core/IconButton';
  import MenuIcon from '@material-ui/icons/Menu';
  
  const useStyles = makeStyles(({ spacing }: Theme) =&gt;
    createStyles({
      root: {
        flexGrow: 1,
      },
      menuButton: {
        marginRight: spacing(2),
      },
      title: {
        flexGrow: 1,
      },
    }),
  );
  
  export default function ButtonAppBar() {
    const classes = useStyles();
  
    return (
      &lt;div className={classes.root}&gt;
        &lt;AppBar position="static"&gt;
          &lt;Toolbar&gt;
            &lt;IconButton edge="start" className={classes.menuButton} color="inherit" aria-label="menu"&gt;
              &lt;MenuIcon /&gt;
            &lt;/IconButton&gt;
            &lt;Typography variant="h6" className={classes.title}&gt;
              MSC
            &lt;/Typography&gt;
            &lt;Button color="inherit"&gt;Login&lt;/Button&gt;
            )}
          &lt;/Toolbar&gt;
        &lt;/AppBar&gt;
      &lt;/div&gt;
    );
  }
  </code></pre>
  
  <p>I want to use the default theme. Am I missing something?</p>