Last example of Mixin class composition tour uses App trait without any explanation

[jrnos]

The last example on page https://docs.scala-lang.org/tour/mixin-class-composition.html defines an object StringIteratorTest extending App i.e. creates an executable using App trait. However, that concept has not been mentioned earlier in the tour neither is explained here. Shouldn't this concept be explained shortly on the same page (or add a link to https://www.scala-lang.org/api/current/scala/App.html)?

[jrnos]

The problematic example referring to App trait has been removed in commit dde4a8d so I'll close this issue as resolved.