span(0),
          span(0),
          span(0),
        ),
      ),
    ]);
    expect(ops).toEqual(['Bar']);
    ops = [];
    
    
    ReactNoop.flush();
    expect(ReactNoop.getChildren()).toEqual([
      div(
        span(1),
        div(
          
          span('X'),
          span(1),
          span(1),
        ),
      ),
    ]);
    expect(ops).toEqual(['Bar', 'Bar']);
  });
  
  
  
  it('calls callback after update is flushed', () => {
    let instance;
    class Foo extends React.Component {