AEM Edge Delivery Service, controlling cache controls and TTL

Hi Arun,

I was able to follow the document from given link and able to add custom headers from .helix/headers - 

Custom headers which are working

url                                Key                    Value
**                              Publisher               EDS

but could not get that working for "cache-control":"max-age=120, public". 

url                                Key                    Value
**                              Cache-Control      max-age=120,public

Can you please guide me here If I am doing anything wrong.