old_contents: import makeClass from 'classnames';
  import PropTypes from 'prop-types';
  import React from 'react';
  import Styles from './Paper.css';
  
  function Paper({backgroundColor, children, className, elevation, style, ...other}) {
    return (
      <div
        {...other}
        className={makeClass(className, Styles.root, Styles[`elevation${elevation}`])}
        style={Object.assign({}, style, {backgroundColor})}
      >
        {children}
      </div>
    );
  }
  
  Paper.defaultProps = {
    backgroundColor: '#fff',
    children: null,
    className: '',
    elevation: 1,
    style: {}
  };
  
  Paper.propTypes = {
    backgroundColor: PropTypes.string,
    children: PropTypes.node,
    className: PropTypes.string,
    elevation: PropTypes.number,
    style: PropTypes.object
  };
  
  export default Paper;
  
new_contents: import makeClass from 'classnames';
  import PropTypes from 'prop-types';
  import React from 'react';
  import Styles from './Paper.css';
  
  class Paper extends React.Component {
    render() {
      const {backgroundColor, children, className, elevation, style, ...other} = this.props;
      return (
        <div
          {...other}
          className={makeClass(className, Styles.root, Styles[`elevation${elevation}`])}
          style={Object.assign({}, style, {backgroundColor})}
        >
          {children}
        </div>
      );
    }
  }
  
  Paper.defaultProps = {
    backgroundColor: '#fff',
    children: null,
    className: '',
    elevation: 1,
    style: {}
  };
  
  Paper.propTypes = {
    backgroundColor: PropTypes.string,
    children: PropTypes.node,
    className: PropTypes.string,
    elevation: PropTypes.number,
    style: PropTypes.object
  };
  
  export default Paper;
  
subject: use class declaration (refs support)