src/atoms/H4.js

import React, { PropTypes } from 'react';

/**
 * A header level 4 component
 */
export default class H4 extends React.Component {
    /**
     * pass in a `title` (string) prop to display a title
     * @return {ReactElement}
     */

    render() {
        <h4 >{this.props.title}</h4>
    }
};

H4.PropTypes = {
    title: React.PropTypes.string
};