function validateChildKeys(node, parentType) {
	  if (typeof node !== 'object') {
	    return;
	  }
	  if (Array.isArray(node)) {
	    for (var i = 0; i < node.length; i++) {
	      var child = node[i];
	      if (ReactElement.isValidElement(child)) {
	        validateExplicitKey(child, parentType);
	      }
	    }
	  } else if (ReactElement.isValidElement(node)) {
	    // This element was passed in a valid location.
	    if (node._store) {
	      node._store.validated = true;
	    }
	  } else if (node) {
	    var iteratorFn = getIteratorFn(node);
	    // Entry iterators provide implicit keys.
	    if (iteratorFn) {
	      if (iteratorFn !== node.entries) {
	        var iterator = iteratorFn.call(node);
	        var step;
	        while (!(step = iterator.next()).done) {
	          if (ReactElement.isValidElement(step.value)) {
	            validateExplicitKey(step.value, parentType);
	          }
	        }
	      }
	    }
	  }
	}
Ensure that every element either is passed in a static location, in an
array with an explicit keys property defined, or in an object literal
with valid key property.

@internal
@param {ReactNode} node Statically passed child of any type.
@param {*} parentType node's parent's type.