function mapChildren(children, func, context) {
	  if (children == null) {
	    return children;
	  }
	  var result = [];
	  mapIntoWithKeyPrefixInternal(children, result, null, func, context);
	  return result;
	}
Maps children that are typically specified as `props.children`.

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

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

@param {?*} children Children tree container.
@param {function(*, int)} func The map function.
@param {*} context Context for mapFunction.
@return {object} Object containing the ordered map of results.