docs: function getTargetDOMElement(binding, view) {
        var target = binding.target;
        // DOM element
        if (target instanceof Element) {
            return target;
        }
        // custom element or custom attribute
        // tslint:disable-next-line:prefer-const
        for (var i = 0, ii = view.controllers.length; i < ii; i++) {
            var controller = view.controllers[i];
            if (controller.viewModel === target) {
                var element = controller.container.get(aureliaPal.DOM.Element);
                if (element) {
                    return element;
                }
                throw new Error("Unable to locate target element for \"" + binding.sourceExpression + "\".");
            }
        }
        throw new Error("Unable to locate target element for \"" + binding.sourceExpression + "\".");
    }