License search expiration date

[stefvp]

I use the api to get the top X expiring license's.
the return I get in my call starts with all the license's without an expiration date (perpetual license's)

api/v1/licenses?limit=50&offset=0&sort=expiration_date&order=asc&expand=false

In this case I ask for the first 50 so if we have 50 perpetual license's then I wouldn't get any usefull info. I could expand the limit but I was wondering if there's a way to only get license's with the expiration_date field filled in, or a way to use search to filter these perpetual license's out of my result