Symfony\Component\DependencyInjection\Definition::setPublic PHP Method

    public function setPublic($boolean)
    {
        $this->public = (bool) $boolean;

        return $this;
    }

 /**
  * @param ContainerBuilder $container
  * @param string           $code
  * @param Definition       $formatter
  * @param array            $extensions
  *
  * @return string
  */
 public function createEnvironment(ContainerBuilder $container, $code, Definition $formatter, array $extensions)
 {
     $loader = new Definition('Twig_Loader_String');
     $loader->setPublic(false);
     $container->setDefinition(sprintf('sonata.formatter.twig.loader.%s', $code), $loader);
     $loaderSelector = new Definition('Sonata\\FormatterBundle\\Twig\\Loader\\LoaderSelector', array(new Reference(sprintf('sonata.formatter.twig.loader.%s', $code)), new Reference('twig.loader')));
     $loaderSelector->setPublic(false);
     $env = new Definition('Twig_Environment', array($loaderSelector, array('debug' => false, 'strict_variables' => false, 'charset' => 'UTF-8')));
     $env->setPublic(false);
     $container->setDefinition(sprintf('sonata.formatter.twig.env.%s', $code), $env);
     $sandboxPolicy = new Definition('Sonata\\FormatterBundle\\Twig\\SecurityPolicyContainerAware', array(new Reference('service_container'), $extensions));
     $sandboxPolicy->setPublic(false);
     $container->setDefinition(sprintf('sonata.formatter.twig.sandbox.%s.policy', $code), $sandboxPolicy);
     $sandbox = new Definition('Twig_Extension_Sandbox', array($sandboxPolicy, true));
     $sandbox->setPublic(false);
     $container->setDefinition(sprintf('sonata.formatter.twig.sandbox.%s', $code), $sandbox);
     $env->addMethodCall('addExtension', array(new Reference(sprintf('sonata.formatter.twig.sandbox.%s', $code))));
     foreach ($extensions as $extension) {
         $env->addMethodCall('addExtension', array(new Reference($extension)));
     }
     $lexer = new Definition('Twig_Lexer', array(new Reference(sprintf('sonata.formatter.twig.env.%s', $code)), array('tag_comment' => array('<#', '#>'), 'tag_block' => array('<%', '%>'), 'tag_variable' => array('<%=', '%>'))));
     $lexer->setPublic(false);
     $container->setDefinition(new Reference(sprintf('sonata.formatter.twig.lexer.%s', $code)), $lexer);
     $env->addMethodCall('setLexer', array(new Reference(sprintf('sonata.formatter.twig.lexer.%s', $code))));
     return sprintf('sonata.formatter.twig.env.%s', $code);
 }