public static function get6to4()
    {
        if (self::$sixToFour === null) {
            self::$sixToFour = self::fromString('2002::/16');
        }

        return self::$sixToFour;
    }
public static function get6to4()
    {
        if (self::$sixToFour === null) {
            self::$sixToFour = self::fromString('2002::/16');
        }

        return self::$sixToFour;
    }
public static function get6to4 ( ) { if ( self :: $ sixToFour === null ) { self :: $ sixToFour = self :: fromString ( '2002::/16' ) ; } return self :: $ sixToFour ; }
Get the 6to4 address IPv6 address range.

@return self
Get the 6to4 address IPv6 address range .