https://doc.rust-lang.org/nightly/nightly-rustc/rustdoc/formats/cache/struct.CacheBuilder.html
CacheBuilder in rustdoc::formats::cache - Rust
This struct is used to wrap the `cache` and `tcx` in order to run `DocFolder`.
rustdocformatscache
https://groups.google.com/g/kilimthreads/c/qLmFklg_yME
fully async integration of kilim with google guava CacheBuilder and LoadingCache
with googlefullyasyncintegrationkilim