Seprate log file in symfony

gistfile1.txt

# app/config/config.yml
services:
    energy_label.logger:
        class:     Symfony\Bridge\Monolog\Logger
        arguments: [app]
        calls:
            - [pushHandler, [@energy_label.logger_handler]]
    energy_label.logger_handler:
        class:     Monolog\Handler\StreamHandler
        arguments: [%kernel.logs_dir%/%kernel.environment%.energy_label_error.log, 200]