Function createPortal

docs/external/js/react-dom.development.js:25045–25056

(children, containerInfo, // TODO: figure out the API for cross-renderer implementation.
  implementation)

  }

  function createPortal(children, containerInfo, // TODO: figure out the API for cross-renderer implementation.
  implementation) {
    var key = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : null;
    return {
      // This tag allow us to uniquely identify this as a React Portal
      $$typeof: REACT_PORTAL_TYPE,
      key: key == null ? null : '' + key,
      children: children,
      containerInfo: containerInfo,
      implementation: implementation
    };
  }

  var ReactVersion = '16.13.1';