public function setNumber($num)
    {
        $num = (int) $num;
        if ($num <= 0) {
            throw new \InvalidArgumentException(sprintf(
                    'Invalid Number "%s" - Polygon Coordinates Number Must Be '
                    . 'Greater Than Zero'
                    , $num
            ));
        }
        $count = count($this->getCoordinates());
        if ($num > $count) {
            throw new \OutOfBoundsException(sprintf(
                    'Given Coodrinates Number "%s" Is Greater Than The Actual '
                    . 'Coordinates Array Size "%s"'
                    , $num, $count
            ));
        }
        $this->count = $num;

        return $this;
    }