DependencyInjection/Compiler/ModifyServiceDefinitionsPass.php
private function configureEmailHelper(ContainerBuilder $container)
    {
        if (!class_exists('Swift_Mailer')) {
            $definition = $container->getDefinition('orkestra.application.helper.email');
            $definition->setClass('Orkestra\Bundle\ApplicationBundle\Helper\EmailHelper\MisconfiguredEmailHelper');
            $definition->setArguments(array());
        }
    }
private function configureEmailHelper(ContainerBuilder $container)
    {
        if (!class_exists('Swift_Mailer')) {
            $definition = $container->getDefinition('orkestra.application.helper.email');
            $definition->setClass('Orkestra\Bundle\ApplicationBundle\Helper\EmailHelper\MisconfiguredEmailHelper');
            $definition->setArguments(array());
        }
    }
Configures the EmailHelper

@param ContainerBuilder $container