Namespacing and reusage of overriden classes.

namespacing.rb

class Overriden
  class << self
    def a
      'GLOBAL'
    end
  end
end

module A
  class Overriden
    class << self
      def a
        'a'
      end
    end
  end
end

module B
  class Overriden
    class << self
      def a
        'b'
      end
    end
  end
end

class GlobalUser
  def self.use
    Overriden.a
  end
end

class AUser
  include A
  def self.use
    Overriden.a
  end
end

class BUser
  include B
  def self.use
    Overriden.a
  end
end

GlobalUser.use # => 'GLOBAL'
AUser.use # => 'a'
BUser.use # => 'b'