How to use the fbjs/lib/ExecutionEnvironment.canUseDOM function in fbjs

};

/**
 * Event names that have already been detected and prefixed (if applicable).
 */
var prefixedEventNames = {};

/**
 * Element to check for prefixes on.
 */
var style = {};

/**
 * Bootstrap if a DOM exists.
 */
if (ExecutionEnvironment.canUseDOM) {
  style = document.createElement('div').style;

  // On some platforms, in particular some releases of Android 4.x,
  // the un-prefixed "animation" and "transition" properties are defined on the
  // style object but the events that fire will still be prefixed, so we need
  // to check if the un-prefixed events are usable, and if not remove them from the map.
  if (!('AnimationEvent' in window)) {
    delete vendorPrefixes.animationend.animation;
    delete vendorPrefixes.animationiteration.animation;
    delete vendorPrefixes.animationstart.animation;
  }

  // Same as above
  if (!('TransitionEvent' in window)) {
    delete vendorPrefixes.transitionend.transition;
  }

checkDebugID(debugID);
    markEnd(debugID, 'unmount');
    emitEvent('onUnmountComponent', debugID);
  },
  onTestEvent: function () {
    emitEvent('onTestEvent');
  }
};

// TODO remove these when RN/www gets updated
ReactDebugTool.addDevtool = ReactDebugTool.addHook;
ReactDebugTool.removeDevtool = ReactDebugTool.removeHook;

ReactDebugTool.addHook(ReactInvalidSetStateWarningHook);
ReactDebugTool.addHook(ReactComponentTreeHook);
var url = ExecutionEnvironment.canUseDOM && window.location.href || '';
if (/[?&]react_perf\b/.test(url)) {
  ReactDebugTool.beginProfiling();
}

module.exports = ReactDebugTool;

checkDebugID(debugID);
    emitEvent('onUnmountComponent', debugID);
  },
  onTestEvent: function () {
    emitEvent('onTestEvent');
  }
};

// TODO remove these when RN/www gets updated
ReactDebugTool.addDevtool = ReactDebugTool.addHook;
ReactDebugTool.removeDevtool = ReactDebugTool.removeHook;

ReactDebugTool.addHook(ReactInvalidSetStateWarningHook);
ReactDebugTool.addHook(ReactComponentTreeHook);
ReactDebugTool.addHook(ReactChildrenMutationWarningHook);
var url = ExecutionEnvironment.canUseDOM && window.location.href || '';
if (/[?&]react_perf\b/.test(url)) {
  ReactDebugTool.beginProfiling();
}

module.exports = ReactDebugTool;

// Inject the runtime into a devtools global hook regardless of browser.
// Allows for debugging when the hook is injected on the page.
/* eslint-enable camelcase */
if (typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ !== 'undefined' && typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.inject === 'function') {
  __REACT_DEVTOOLS_GLOBAL_HOOK__.inject({
    CurrentOwner: ReactCurrentOwner,
    InstanceHandles: ReactInstanceHandles,
    Mount: ReactMount,
    Reconciler: ReactReconciler,
    TextComponent: ReactDOMTextComponent
  });
}

if (process.env.NODE_ENV !== 'production') {
  var ExecutionEnvironment = require('fbjs/lib/ExecutionEnvironment');
  if (ExecutionEnvironment.canUseDOM && window.top === window.self) {

    // First check if devtools is not installed
    if (typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ === 'undefined') {
      // If we're in Chrome or Firefox, provide a download link if not installed.
      if (navigator.userAgent.indexOf('Chrome') > -1 && navigator.userAgent.indexOf('Edge') === -1 || navigator.userAgent.indexOf('Firefox') > -1) {
        console.debug('Download the React DevTools for a better development experience: ' + 'https://fb.me/react-devtools');
      }
    }

    // If we're in IE8, check to see if we are in compatibility mode and provide
    // information on preventing compatibility mode
    var ieCompatibilityMode = document.documentMode && document.documentMode < 8;

    process.env.NODE_ENV !== 'production' ? warning(!ieCompatibilityMode, 'Internet Explorer is running in compatibility mode; please add the ' + 'following tag to your HTML to prevent this from happening: ' + '') : undefined;

    var expectedFeatures = [

var ExecutionEnvironment = require('fbjs/lib/ExecutionEnvironment');
var ReactPerf = require('./ReactPerf');

var camelizeStyleName = require('fbjs/lib/camelizeStyleName');
var dangerousStyleValue = require('./dangerousStyleValue');
var hyphenateStyleName = require('fbjs/lib/hyphenateStyleName');
var memoizeStringOnly = require('fbjs/lib/memoizeStringOnly');
var warning = require('fbjs/lib/warning');

var processStyleName = memoizeStringOnly(function (styleName) {
  return hyphenateStyleName(styleName);
});

var hasShorthandPropertyBug = false;
var styleFloatAccessor = 'cssFloat';
if (ExecutionEnvironment.canUseDOM) {
  var tempStyle = document.createElement('div').style;
  try {
    // IE8 throws "Invalid argument." if resetting shorthand style properties.
    tempStyle.font = '';
  } catch (e) {
    hasShorthandPropertyBug = true;
  }
  // IE8 only supports accessing cssFloat (standard) as styleFloat
  if (document.documentElement.style.cssFloat === undefined) {
    styleFloatAccessor = 'styleFloat';
  }
}

if (process.env.NODE_ENV !== 'production') {
  // 'msTransform' is correct, but the other prefixes should be capitalized
  var badVendoredStyleNamePattern = /^(?:webkit|moz|o)[A-Z]/;

* @internal
 */
var setInnerHTML = function (node, html) {
  node.innerHTML = html;
};

// Win8 apps: Allow all html to be inserted
if (typeof MSApp !== 'undefined' && MSApp.execUnsafeLocalFunction) {
  setInnerHTML = function (node, html) {
    MSApp.execUnsafeLocalFunction(function () {
      node.innerHTML = html;
    });
  };
}

if (ExecutionEnvironment.canUseDOM) {
  // IE8: When updating a just created node with innerHTML only leading
  // whitespace is removed. When updating an existing node with innerHTML
  // whitespace in root TextNodes is also collapsed.
  // @see quirksmode.org/bugreports/archives/2004/11/innerhtml_and_t.html

  // Feature detection; only IE8 is known to behave improperly like this.
  var testElement = document.createElement('div');
  testElement.innerHTML = ' ';
  if (testElement.innerHTML === '') {
    setInnerHTML = function (node, html) {
      // Magic theory: IE8 supposedly differentiates between added and updated
      // nodes when processing innerHTML, innerHTML on updated nodes suffers
      // from worse whitespace behavior. Re-adding a node like this triggers
      // the initial and more favorable whitespace behavior.
      // TODO: What to do on a detached node?
      if (node.parentNode) {

* @internal
 */
var setInnerHTML = function (node, html) {
  node.innerHTML = html;
};

// Win8 apps: Allow all html to be inserted
if (typeof MSApp !== 'undefined' && MSApp.execUnsafeLocalFunction) {
  setInnerHTML = function (node, html) {
    MSApp.execUnsafeLocalFunction(function () {
      node.innerHTML = html;
    });
  };
}

if (ExecutionEnvironment.canUseDOM) {
  // IE8: When updating a just created node with innerHTML only leading
  // whitespace is removed. When updating an existing node with innerHTML
  // whitespace in root TextNodes is also collapsed.
  // @see quirksmode.org/bugreports/archives/2004/11/innerhtml_and_t.html

  // Feature detection; only IE8 is known to behave improperly like this.
  var testElement = document.createElement('div');
  testElement.innerHTML = ' ';
  if (testElement.innerHTML === '') {
    setInnerHTML = function (node, html) {
      // Magic theory: IE8 supposedly differentiates between added and updated
      // nodes when processing innerHTML, innerHTML on updated nodes suffers
      // from worse whitespace behavior. Re-adding a node like this triggers
      // the initial and more favorable whitespace behavior.
      // TODO: What to do on a detached node?
      if (node.parentNode) {

function shouldRetry(attempt: number): boolean {
      return (
        ExecutionEnvironment.canUseDOM &&
        attempt <= nonNullRetryDelays.length
      );
    }

for (var i = 0; i < bookKeeping.ancestors.length; i++) {
    targetInst = bookKeeping.ancestors[i];
    ReactEventListener._handleTopLevel(bookKeeping.topLevelType, targetInst, bookKeeping.nativeEvent, getEventTarget(bookKeeping.nativeEvent));
  }
}

function scrollValueMonitor(cb) {
  var scrollPosition = getUnboundedScrollPosition(window);
  cb(scrollPosition);
}

var ReactEventListener = {
  _enabled: true,
  _handleTopLevel: null,

  WINDOW_HANDLE: ExecutionEnvironment.canUseDOM ? window : null,

  setHandleTopLevel: function (handleTopLevel) {
    ReactEventListener._handleTopLevel = handleTopLevel;
  },

  setEnabled: function (enabled) {
    ReactEventListener._enabled = !!enabled;
  },

  isEnabled: function () {
    return ReactEventListener._enabled;
  },

  /**
   * Traps top-level events by using event bubbling.
   *

}
  if (eventsFired === 0) {
    ReactEventListener._handleTopLevel(bookKeeping.topLevelType, window, '', bookKeeping.nativeEvent, getEventTarget(bookKeeping.nativeEvent));
  }
}

function scrollValueMonitor(cb) {
  var scrollPosition = getUnboundedScrollPosition(window);
  cb(scrollPosition);
}

var ReactEventListener = {
  _enabled: true,
  _handleTopLevel: null,

  WINDOW_HANDLE: ExecutionEnvironment.canUseDOM ? window : null,

  setHandleTopLevel: function (handleTopLevel) {
    ReactEventListener._handleTopLevel = handleTopLevel;
  },

  setEnabled: function (enabled) {
    ReactEventListener._enabled = !!enabled;
  },

  isEnabled: function () {
    return ReactEventListener._enabled;
  },

  /**
   * Traps top-level events by using event bubbling.
   *