It is a Jest-ism that shouldn't be in our open source package.
People using Jest can implement a similar pattern directly.
touches: [{pageX: x, pageY: y}],
    };
  },
  Simulate: null,
  SimulateNative: {},
};
/**
 * Exports:
 *
 * - `ReactTestUtils.Simulate.click(Element)`
 * - `ReactTestUtils.Simulate.mouseMove(Element)`
 * - `ReactTestUtils.Simulate.change(Element)`
 * - ... (All keys from event plugin `eventTypes` objects)
 */
function makeSimulator(eventType) {
  return function(domNode, eventData) {
    invariant(
      !React.isValidElement(domNode),
      'TestUtils.Simulate expected a DOM node as the first argument but received ' +
        'a React element. Pass the DOM node you wish to simulate the event on instead. ' +
        'Note that TestUtils.Simulate will not work if you are using shallow rendering.',
    );
    invariant(
      !ReactTestUtils.isCompositeComponent(domNode),
      'TestUtils.Simulate expected a DOM node as the first argument but received ' +
        'a component instance. Pass the DOM node you wish to simulate the event on instead.',
    );
    const dispatchConfig =
      EventPluginRegistry.eventNameDispatchConfigs[eventType];
    const fakeNativeEvent = new Event();