Used as a more flexible alternative to Clojure's core `memoization` function. Memoized functions built using `memo` will respond to the core.memo manipulable memoization utilities. As a nice bonus, you can use `memo` in place of `memoize` without any additional changes. The default way to use this function is to simply apply a function that will be memoized. Additionally, you may also supply a map of the form `'{[42] 42, [108] 108}` where keys are a vector mapping expected argument values to arity positions. The map values are the return values of the memoized function. You can access the memoization cache directly via the `:clojure.core.memoize/cache` key on the memoized function's metadata. However, it is advised to use the core.memo primitives instead as implementation details may change over time.