Are you sure you want to use Vaadin as an example for anything? :D
This code, while very extreme, shows the difference between knowing the syntax and knowing how to program. While still valid, creating such structure introduces almost impossible way of telling what is being used, overwritten etc.
This is one of many examples, that look like this in the web components area. Paper elements from the Polymer team are not much better in this :)
I see, but this proves nothing. Saying that "there are many examples of bad practices" can be revoked with "there are many examples of good practices". You don't stretch a rubber band the the max just because it can be stretched :)
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