workspace will cache everything in memory if this service doesn't exist in workspace. now this being exist, workspace will start to put things such as text, tree, compilation either kick out from memory or save it to temporary storage.

this should reduce memory foot print once things become idle, but this doesn't help memory footprint while feature is running.

with this service, once OOP become idle, memory foot print goes down to about 700MB to 1 GB. but still while code lens run, memory goes up to 3GB.