function forEach(children, func, context) {
	  var index = 0;

	  _react2['default'].Children.forEach(children, function (child) {
	    if (!_react2['default'].isValidElement(child)) {
	      return;
	    }

	    func.call(context, child, index++);
	  });
	}
Finds children that are typically specified as `props.children`,
but only iterates over children that are "valid components".

The provided forEachFunc(child, index) will be called for each
leaf child with the index reflecting the position relative to "valid components".

@param {?*} children Children tree container.
@param {function(*, int)} func.
@param {*} context Context for func.
@returns {array} of children that meet the func return statement