Property details pages are missing "read-only" notion

[eseidelGoogle]

For example Map.values is readonly.

Which you can see from the main Map page:
https://api.dartlang.org/stable/1.20.1/dart-core/Map-class.html

But that information is lost in the property page:
https://api.dartlang.org/stable/1.20.1/dart-core/Map/values.html

I'm not sure where the readonly comes from since I don't see it in the source:
https://github.com/dart-lang/sdk/blob/master/sdk/lib/core/map.dart#L243

[eseidelGoogle]

I see, I think the readonly comes because it only has get and not set. Still, the property page should say this. :)

[srawlins]

This is still true today. I think that this doesn't come up frequently because setters are not nearly as common as getters. I searched the Dart SDK for a while, and finally found Counter.value. The page shows both the getter impl, and the setter impl, but very awkwardly, IMO. I think the distinction should be made more clear, especially in the case described above, where the property is "read-only."