Two different headers for the same route

[pcmanprogrammeur]

Hi,
I would like to create a route to generate a csv but if there is an exception to generate a json response.
Is it possible to return two different headers please ?
I tried this without success

    format_listener:
        rules:
            - { path: .*/my_route/.*, prefer_extension: true, fallback_format: ~, priorities: [ json, csv ] }

Thanks for your help.