code: function transitionGroupWeb (Component, createElement) {
    return (function (Component) {
      function TransitionGroup () {
        Component.apply(this, arguments);
      }
  
      if ( Component ) TransitionGroup.__proto__ = Component;
      TransitionGroup.prototype = Object.create( Component && Component.prototype );
      TransitionGroup.prototype.constructor = TransitionGroup;
  
      TransitionGroup.prototype.render = function render () {
        var tag = this.props.tag || 'span';
        return createElement(tag, null)
      };
  
      return TransitionGroup;
    }(Component))
  }
docs: unfinished