Currently, if you define `shouldComponentUpdate` on `React.PureComponent` nothing bad happens and it acts like `React.Component` https://jsfiddle.net/jekmdfva/

We should probably warn in dev since it defaults the point of `PureComponent`
*/
  _updateRenderedComponent: function(transaction, context) {
    var nextRenderedElement = this._renderValidatedComponent();
    this._updateRenderedComponentWithNextElement(
      transaction,
      context,
      nextRenderedElement,
      false ,
    );
  },
  /**
   * Call the component's `render` method and update the DOM accordingly.
   *
   * @param {ReactReconcileTransaction} transaction
   * @internal
   */
  _updateRenderedComponentWithNextElement: function(
    transaction,
    context,
    nextRenderedElement,
    safely,
  ) {
    var prevComponentInstance = this._renderedComponent;
    var prevRenderedElement = prevComponentInstance._currentElement;
    var debugID = 0;
    if (__DEV__) {
      debugID = this._debugID;
    }
    if (shouldUpdateReactComponent(prevRenderedElement, nextRenderedElement)) {
      ReactReconciler.receiveComponent(