Minor Description
From https://github.com/apache/camel/pull/5088#discussion_r576060177:
That API is not really for end users, as that would mean they build those model classes outside the DSL and then take that model (which is a route) and add to a route (doesnt make so much sense). We should possibly mark in the javadoc that this is only for internal usage. And maybe come up with a different name, and deprecate the old name.