function eachProp(obj, func) {
        var prop;
        for (prop in obj) {
            if (obj.hasOwnProperty(prop)) {
                if (func(obj[prop], prop)) {
                    break;
                }
            }
        }
    }
Cycles over properties in an object and calls a function for each
property value. If the function returns a truthy value, then the
iteration is stopped.