Assetic groups in Symfony2

conig.yml

assetic:
    debug:          %kernel.debug%
    use_controller: false
    bundles:        [ YourBundle ]
    assets:
        frontend:
            inputs:
                - @YourBundle/Resources/public/css/cssreset-min.css
                - @YourBundle/Resources/public/css/fonts.css
                - @YourBundle/Resources/less/layout.less
                - @YourBundle/Resources/less/homepage.less

# And then in your base.html.twig:
#{% block stylesheets %}
#    {% stylesheets "@frontend" %}
#        <link href="{{ asset_url }}" type="text/css" rel="stylesheet" media="all" />
#    {% endstylesheets %}
#{% endblock %}