The append_features method of Module

In the same way that the class could include some singleton methods,the Module could include some singleton methods,too.But if we implement a class which include a Module which contians some singleton methods,does these methods become to the class's singleton methods?The answer is 'no'.There is a hook called append_features that we can override.It's called with a parameter that is the destination class or module.For an example of its use,see the following codes:

ruby 代码

module MyMod
  def MyMod.append_features(someClass)
    def someClass.modmeth
      puts "Module (class) method"
    end
    super
  end
end
class AppendFeatures
  include MyMod
  def initialize

  end
end

AppendFeatures.modmeth

Note:
you should call the "super" when you override the append_features method.

It's very interesting.
These code copy from the <ruby way=""> book.</ruby>