public static function randomElements(array $array = array('a', 'b', 'c'), $count = 1, $allowDuplicates = false)
    {
        $allKeys = array_keys($array);
        $numKeys = count($allKeys);

        if (!$allowDuplicates && $numKeys < $count) {
            throw new \LengthException(sprintf('Cannot get %d elements, only %d in array', $count, $numKeys));
        }

        $highKey = $numKeys - 1;
        $keys = $elements = array();
        $numElements = 0;

        while ($numElements < $count) {
            $num = mt_rand(0, $highKey);

            if (!$allowDuplicates) {
                if (isset($keys[$num])) {
                    continue;
                }
                $keys[$num] = true;
            }

            $elements[] = $array[$allKeys[$num]];
            $numElements++;
        }

        return $elements;
    }