function forEachChildren(children, forEachFunc, forEachContext) {
	  if (children == null) {
	    return children;
	  }
	  var traverseContext = ForEachBookKeeping.getPooled(forEachFunc, forEachContext);
	  traverseAllChildren(children, forEachSingleChild, traverseContext);
	  ForEachBookKeeping.release(traverseContext);
	}
Iterates through children that are typically specified as `props.children`.

See https://facebook.github.io/react/docs/top-level-api.html#react.children.foreach

The provided forEachFunc(child, index) will be called for each
leaf child.

@param {?*} children Children tree container.
@param {function(*, int)} forEachFunc
@param {*} forEachContext Context for forEachContext.