Chef Libraries - Class and Use Confusion

Chef Infra (archive)
1 
I have been using Chef for about 4 years and I know a lot has changed or maybe I really fulling understood/grok'ed this particular subject.

I need a little help understanding Chef libraries and where method
definitions are held in the class tree. I am trying to teach some of my
colleges about libraries and custom resources and found that I could not
answer the questions I pose below.

In the past I have always written libaries one of two ways

###########
# way one #
###########

module Foo
  module Bar

    def my_method
      true
    end
    
  end
end

Chef::Recipe.send(:include, ::Foo::Bar)
Chef::Resource.send(:include, ::Foo::Bar)
Chef::Provider.send(:include, ::Foo::Bar)

Now in any Chef recipe I can use my_method without any class prefixing (just call my_method)

I know this is some what or very much discouraged as monkey patching
your own method names into the "official" class space is likely to do harm
when your name overwrites a previously existing method

###########
# way two #
###########

From Customizing Chef (Cowie) -- I also have been using this format

class Chef::Recipe
  class Company

    def self.my_method
      true
    end

  end
end

Now in any Chef recipe I can use Chef::Recipe::Company.my_method() or Company.my_method()

This puts all of my methods in a custom namespace which prevents
conflicts. The only very small issue is that I have to prefix the calls
with their container class.

################
# Question One #
################

I have never bothered to ask this but now I will. In the discouraged paradigm of including my custom methods in 3 namspace classs

Chef::Recipe.send(:include, ::Foo::Bar)
Chef::Resource.send(:include, ::Foo::Bar)
Chef::Provider.send(:include, ::Foo::Bar)

I get whey have to beincluded into Chef::Recipe -- what is the need for the include into Chef::Resource and Chef::Provider?

################
# My Confusion #
################

I was recently looking at some of the Chef maintained community
cookbooks and came across a lot of library files that had plain old
method definitions such as:

def my_method
  true
end

And then these were used in Recipes with their bare names, as if they had just been automatically include into Chef::Recipe.

################
# Question Two #
################

When you define a method in a library file that does not have an defined outer class or module:

(1) Which class do these methods live in?
(2) Can they be used across cookbooks
(3) Can you do damaging things with this seeming monkey patching by
    simply defining a method in a library file that overwrites and existing
    method.

If there is any good articles that explain this please just point me there. Thanks