toucan2.tools.hydrate/simple-hydrate [model₁ k₂ instance] Implementations should return a version of map instance with the key k added.
simple-hydrate is defined in toucan2.tools.hydrate (toucan2/tools/hydrate.clj:483).
It caches methods using a methodical.impl.cache.watching.WatchingCache.
It uses the method combination methodical.impl.combo.threaded.ThreadingMethodCombination with the threading strategy :thread-last.