having to significantly refactor this code because turns out i probably actually do want `Object.create(null)` instead of `Map` and `Array.from()` instead of `Set`
@Lady well there’s a sentence to read without any context
@Lady oh i just mean i have no idea in what context this would make sense to say (though i’m sure it exists)
@aescling Map and Set are always mutable and do not participate in general JavaScript property access semantics (enumerability, writability, etc.)
[there is a proposal for readonly Maps and Sets but it’s still only Stage 1]
when you do actually want to take advantage of javascript property semantics (enumerability, writability, getters/setters), you need to use ordinary objects to do it. `Object.create(null)` is a great way to do this when you only need the property semantics and not the prototype chain.
@aescling in my case, it is very important that my mappings do not change after object creation, which is easy to achieve on ordinary objects with `Object.freeze()` but impossible to guarantee with Maps. since my keys are all strings, `Object.create(null)` is the simplest and most straightforward approach.