Prog75 

Simple wrapers of vallue with TTL as: public T GetOrCreate(Func<T> factory) => IsExpired ? value = EnsureValue(factory) : value!;

Very light DI, but using only factory (Source of inspiration: https://github.com/reactiveui/splat)

Another wrapper for Httpclient

Static throw helper + HashCoceCombiner class (from MS) + some extensions + Option (as in Rust)