public function setNumber( $number )
    {
        $number = preg_replace( '/^0+|\D/', '', $number );

        if (strlen( $number ) !== 9 && strlen( $number ) !== 8) {
            throw new InvalidArgumentException( sprintf( 'Invalid Number (%s)', $number ) );
        }

        $this->number = $number;

        return $this;
    }
public function setNumber( $number )
    {
        $number = preg_replace( '/^0+|\D/', '', $number );

        if (strlen( $number ) !== 9 && strlen( $number ) !== 8) {
            throw new InvalidArgumentException( sprintf( 'Invalid Number (%s)', $number ) );
        }

        $this->number = $number;

        return $this;
    }
@param  string $number

@return $this