class_c.rb

class C
  include A
  include B
end

C.new.foo #will call B.foo, then A.foo - method composition

module_a.rb

module A
  def foo
    super if defined?(super)
    do_stuff()
  end
end

module_b.rb

module B
  def foo
    do_other_stuff
    super if defined?(super)
    do_some_more_stuff
  end
end