public function addGetParam($param, $value = true)
  {
    // Validate
    if (!is_scalar($param))
    {
      throw new \Exception("Param name must be scalar");
    }

    // Filter
    if (is_string($value))
    {
      $value = trim($value);
    }

    // Set
    $this->queryParams[trim($param)] = $value;

    return $this;
  }