content: import React, { Component } from 'react';
  import PropTypes from 'prop-types';
  
  const propTypes = {
    width: PropTypes.string,
    children: PropTypes.node,
  };
  
  const defaultProps = {
    width: null,
    children: null,
  };
  
  const childContextTypes = {
    mediaFeatures: PropTypes.shape({
      width: PropTypes.string,
    }),
  };
  
  class MediaFeatures extends Component {
  
    getChildContext() {
      const { width } = this.props;
      const mediaFeatures = width ? { width } : null;
      return { mediaFeatures };
    }
  
    render() {
      return <div>{ this.props.children }</div>;
    }
  }
  
  MediaFeatures.propTypes = propTypes;
  
  MediaFeatures.defaultProps = defaultProps;
  
  MediaFeatures.childContextTypes = childContextTypes;
  
  export default MediaFeatures;
  