问Symfony2安全配置-如何并行使用两个防火墙

EN

security:
    firewalls:
        frontend:
            pattern:    ^/
            provider: fe_users
            anonymous: ~
            form_login:
                username_parameter: _email
                login_path:  _login
                check_path:  _login_check
                remember_me: true
                default_target_path: _profile
                #always_use_default_target_path: true
            logout:
                path: /logout
                target: /
            remember_me:
                key: MiPassphrase
                lifetime: 1800
                path: /.*
                domain: ~
        backend:
            pattern:   ^/backend
            provider: be_users
            anonymous: ~
            http_basic:
                realm: ""

    access_control:
        - { path: ^/backend$, roles: ROLE_ADMIN }
        - { path: ^/, roles: IS_AUTHENTICATED_ANONYMOUSLY }

    encoders:
        vv\xx\Entity\User:
            algorithm: bcrypt
        Symfony\Component\Security\Core\User\User: plaintext

    providers:
        fe_users:
            entity: { class: vvxx:User, property: email }
        be_users:
            memory:
                users:
                    d: { password: c, roles: 'ROLE_ADMIN' }