Currently if React is not loaded, ReactDOM shows this:

<img width="664" alt="screen shot 2017-08-08 at 3 36 52 pm" src="https://user-images.githubusercontent.com/810438/29077217-784c7624-7c4f-11e7-88bc-b055407523a9.png">

We should throw a nicer error message in the entry point I think.
</svg>,
          )}
          <p {...expectHTML} />
        </div>,
      );
      assertNamespacesMatch(
        <svg {...expectSVG}>
          <svg {...expectSVG}>
            {usePortal(<div {...expectHTML} />)}
            <image {...expectSVG} />
          </svg>
          <image {...expectSVG} />
        </svg>,
      );
    });
    it('should keep track of namespace across portals (complex)', () => {
      assertNamespacesMatch(
        <div {...expectHTML}>
          {usePortal(
            <svg {...expectSVG}>
              <image {...expectSVG} />
            </svg>,
          )}
          <p {...expectHTML} />
          <svg {...expectSVG}>
            <image {...expectSVG} />
          </svg>
          <svg {...expectSVG}>
            <svg {...expectSVG}>
              <image {...expectSVG} />