old_contents: import React from 'react';
  import { findDOMNode } from 'react-dom';
  import ReactTestUtils from 'react-dom/test-utils';
  import Column from '../src/Column';
  
  
  describe('Column', () => {
  
    it('Should output a null', () => {
      const instance = ReactTestUtils.renderIntoDocument(
        <Column />
      );
  
      const instanceDom = findDOMNode(instance);
      assert.equal(instanceDom, null);
    });
  
  });
  
new_contents: import React from 'react';
  import { findDOMNode } from 'react-dom';
  import ReactTestUtils from 'react-dom/test-utils';
  import Column from '../src/Column';
  
  describe('Column', () => {
    it('Should output a null', () => {
      const instance = ReactTestUtils.renderIntoDocument(<Column />);
  
      const instanceDom = findDOMNode(instance);
      assert.equal(instanceDom, null);
    });
  });
  
subject: Update tests