# What is the best way to get it to put out a, b, c
# without erroring about the superclass. The module
# inclusion order should not matter. In other words,
# I should be able to include A then B or B then A 
# and either way all the letters a, b, and c are 
# printed out (though not necessarily in that exact order)

module TopLevel
  def foo(*args)
    # do nothing
  end
end

module A
  def foo
    super
    puts 'a'
  end
end

module B
  def foo
    super
    puts 'b'
  end
end

class C
  include TopLevel
  include A
  include B

  def foo
    super
    puts 'c'
  end
end

C.new.foo