The Code Service provided by cql-exec is not particulary effective at working with remote caches of Fhir Defined Value Sets. We should be reference ValueSets in a CQL Statement and then have them loaded from a Server based on the id property being the ValueSet URL
This was the basic goal of cql-exec-vsac. Unfortunately, they have not kept up with the changes to VSAC and (SVS API)[https://www.nlm.nih.gov/vsac/support/usingvsac/vsacsvsapiv2.html] is being deprecated in favor of the Fhir Terminology Service. That is why this library has been created.
There is inbuilt caching since these servers are usually slow.