@material-ui/core UI를 Class로 구현하기

https://github.com/mui-org/material-ui/issues/15820

@material-ui/styles: Usage in a Class Component? · Issue #15820 · mui-org/material-ui

import { withStyles } from '@material-ui/core/styles';

const useStyles = theme => ({
    fab: {
      position: 'fixed',
      bottom: theme.spacing(2),
      right: theme.spacing(2),
    },
  });

class LoginComponent extends Component {
       render() {
                const { classes } = this.props;
                {/** your UI components... */}
          }
} 

export default withStyles(useStyles)(LoginComponent)