text: import React, { Component } from 'react';
  import PropTypes from 'prop-types';
  import classNames from 'classnames';
  
  const propTypes = {
    children: PropTypes.node,
    className: PropTypes.string,
    fixed: PropTypes.bool,
    tag: PropTypes.oneOfType([PropTypes.func, PropTypes.string])
  };
  
  const defaultProps = {
    tag: 'header',
    fixed: false
  };
  
  class AppHeader extends Component {
    componentDidMount() {
      this.isFixed(this.props.fixed);
    }
  
    isFixed(fixed) {
      if (fixed) { document.body.classList.add('header-fixed'); }
    }
  
    // breakpoint(breakpoint) {
    //   return breakpoint || '';
    // }
  
    render() {
      const { className, children, tag: Tag, ...attributes } = this.props;
  
      delete attributes.fixed
  
      const classes = classNames(className, 'app-header', 'navbar');
  
      return (
        <Tag className={classes} {...attributes}>
          {children}
        </Tag>
      );
    }
  }
  
  AppHeader.propTypes = propTypes;
  AppHeader.defaultProps = defaultProps;
  
  export default AppHeader;
  