public function setPadding($value)
    {
        if (!is_numeric($value) || $value < 0 || $value > 0.4) {
            throw new \InvalidArgumentException(
                "Padding '$value' out of range. ".
                "Values in the range [0.0, 0.4] are allowed.");
        }
        $this->padding = (float)$value;
        return $this;
    }