Function validateExplicitKey

transformjs/react/example/index.js:3141–3165

* Warn if the element doesn't have an explicit key assigned to it. * This element is in an array. The array could grow and shrink or be * reordered. All children that haven't already been validated are required to * have a "key" property assigned to it. Error statuses are cached so a warning

(element, parentType)

	 * @param {*} parentType element's parent's type.
	 */
	function validateExplicitKey(element, parentType) {
	  if (!element._store || element._store.validated || element.key != null) {
	    return;
	  }
	  element._store.validated = true;

	  var memoizer = ownerHasKeyUseWarning.uniqueKey || (ownerHasKeyUseWarning.uniqueKey = {});

	  var currentComponentErrorInfo = getCurrentComponentErrorInfo(parentType);
	  if (memoizer[currentComponentErrorInfo]) {
	    return;
	  }
	  memoizer[currentComponentErrorInfo] = true;

	  // Usually the current owner is the offender, but if it accepts children as a
	  // property, it may be the creator of the child that's responsible for
	  // assigning it a key.
	  var childOwner = '';
	  if (element && element._owner && element._owner !== ReactCurrentOwner.current) {
	    // Give the component that originally created this child.
	    childOwner = ' It was passed a child from ' + element._owner.getName() + '.';
	  }

	  process.env.NODE_ENV !== 'production' ? warning(false, 'Each child in an array or iterator should have a unique "key" prop.' + '%s%s See https://fb.me/react-warning-keys for more information.%s', currentComponentErrorInfo, childOwner, ReactComponentTreeHook.getCurrentStackAddendum(element)) : void 0;
	}

	/**
	 * Ensure that every element either is passed in a static location, in an