*feature*

>Warning: A component is `contentEditable` and contains `children` managed by React. It is now your responsibility to guarantee that none of those nodes are unexpectedly modified or duplicated. This is probably not intentional.

It would help heaps if I would know _which_ component is causing this.
render() {
          return <a>{this.props.children}</a>;
        }
      }
      ReactTestUtils.renderIntoDocument(<Link><div><Link /></div></Link>);
      expectDev(console.error.calls.count()).toBe(6);
      expectDev(
        normalizeCodeLocInfo(console.error.calls.argsFor(5)[0]),
      ).toContain(
        '\n    in a (at **)' +
          '\n    in Link (at **)' +
          '\n    in div (at **)' +
          '\n    in a (at **)' +
          '\n    in Link (at **)',
      );
    });
    it('should warn about incorrect casing on properties (ssr)', () => {
      spyOn(console, 'error');
      ReactDOMServer.renderToString(
        React.createElement('input', {type: 'text', tabindex: '1'}),
      );
      expectDev(console.error.calls.count()).toBe(1);
      expectDev(console.error.calls.argsFor(0)[0]).toContain('tabIndex');
    });