I *this* this whole `if`/`elsif`/`else` thing can be replaced with something like this:

```ruby
@memoized_value_from[memoization_key] = options.fetch(first_key) do
  options.fetch(:default) do
    if_required_and_missing.call
  end
end
```

It's kind of a lot of `fetch`ing, but it avoids trying to track the three possible branches which are very similar and each have a `return` in them.

What do you think?