public function point($int_x, $int_y)
    {
        if (is_double($int_x)) {
            $int_x = (integer) $int_x;
        }

        if (is_double($int_y)) {
            $int_y = (integer) $int_y;
        }

        if ((!is_integer($int_x) || !is_integer($int_y)) || $int_x < 0 || $int_y < 0) {
            throw new \InvalidArgumentException('Coordinates must be composed of two positive integers!');
        }

        $this->arr_points[] = array($int_x, $int_y);

        return $this;
    }