text: import React from 'react';
  import { configure, shallow } from 'enzyme';
  import Adapter from 'enzyme-adapter-react-16';
  import Header from './Header';
  
  configure({ adapter: new Adapter() });
  
  test("Header should display it's left component", () => {
    const left = "I'm the left component";
    const header = shallow(<Header left={left} />);
    expect(header.first('left').text()).toEqual(left);
  });
  