text: import React from 'react';
  import ReactDOM from 'react-dom';
  
  import { Link, NavLink } from 'react-router-dom';
  
  const Header = props => {
    return (
      <header>
        <h1>Routing!</h1>
        <nav>
          <ul>
            <li>
              <Link to="/">Home</Link>
            </li>
            <li>
              <NavLink to="/history" activeClassName="here">History</NavLink>
            </li>
          </ul>
        </nav>
      </header>
    );
  };
  
  export default Header;