private function hasArrayDuplicates($array)
    {
        $compare = array();
        foreach ($array as $element) {
            // duplicate element found
            if (in_array($element, $compare, true)) {
                return true;
            } else {
                // add element to temporary array to check for duplicates
                $compare [] = $element;
            }
        }

        return false;
    }