Projucer as an example of using the GUI Editor?

Hi,

Can the Projucer be used an example of using the GUI Editor?

If not, are there other example projects using the GUI Editor with a
tabbedComponent, by someone knowledgable in the right vs. wrong ways
to design/construct such a GUI?

Background:
As you have already guessed, I’m a noob with JUCE and GUI Editor.
I have read thru all the juce.com tutorials, as well as the Redwood Audtio tutorial.
i can open Projucer.jucer in Projucer.
But I have not yet found a .cpp/.h file which gives me the GUI Editor tabs/menus.
Using my own simple project, I have searched Projucer files for terms like
BEGIN_JUCER_METADATA and tabBarDepth, yet those Projucer files do not give me GUI Editor.
I have not found the term “generated GUI class” in Projucer files.
Perhaps Projucer was not built with GUI Editor?