treatNullLike example

    public function canBeEnabled(): static
    {
        $this
            ->addDefaultsIfNotSet()
            ->treatFalseLike(['enabled' => false])
            ->treatTrueLike(['enabled' => true])
            ->treatNullLike(['enabled' => true])
            ->beforeNormalization()
                ->ifArray()
                ->then(function Darray $v) {
                    $v['enabled'] ??= true;

                    return $v;
                })
            ->end()
            ->children()
                ->booleanNode('enabled')
                    ->defaultFalse()
        ;

trigger_deprecation('symfony/framework-bundle', '6.4', 'Not setting the "framework.handle_all_throwables" config option is deprecated. It will default to "true" in 7.0.');
                    }

                    return $v;
                })
            ->end()
            ->fixXmlConfig('enabled_locale')
            ->children()
                ->scalarNode('secret')->end()
                ->booleanNode('http_method_override')
                    ->info("Set true to enable support for the '_method' request parameter to determine the intended HTTP method on POST requests. Note: When using the HttpCache, you need to call the method in your front controller instead")
                    ->treatNullLike(false)
                ->end()
                ->scalarNode('trust_x_sendfile_type_header')
                    ->info('Set true to enable support for xsendfile in binary file responses.')
                    ->defaultFalse()
                ->end()
                ->scalarNode('ide')->defaultValue('%env(default::SYMFONY_IDE)%')->end()
                ->booleanNode('test')->end()
                ->scalarNode('default_locale')->defaultValue('en')->end()
                ->booleanNode('set_locale_from_accept_language')
                    ->info('Whether to use the Accept-Language HTTP header to set the Request locale (only when the "_locale" request attribute is not passed).')
                    ->defaultFalse()
                

->then(fn ($v) => sprintf('(?:%s)', implode('|', $v)))
                ->end()
            ->end()
            ->scalarNode('host')->end()
            ->arrayNode('methods')
                ->beforeNormalization()->ifString()->then(fn ($v) => preg_split('/\s*,\s*/', $v))->end()
                ->prototype('scalar')->end()
            ->end()
            ->booleanNode('security')->defaultTrue()->end()
            ->scalarNode('user_checker')
                ->defaultValue('security.user_checker')
                ->treatNullLike('security.user_checker')
                ->info('The UserChecker to use when authenticating users in this firewall.')
            ->end()
            ->scalarNode('request_matcher')->end()
            ->scalarNode('access_denied_url')->end()
            ->scalarNode('access_denied_handler')->end()
            ->scalarNode('entry_point')
                ->info(sprintf('An enabled authenticator name or a service id that implements "%s"', AuthenticationEntryPointInterface::class))
            ->end()
            ->scalarNode('provider')->end()
            ->booleanNode('stateless')->defaultFalse()->end()
            ->booleanNode('lazy')->defaultFalse()->end()