title: Extending a Ruby module in another module, including the module methods
body: <p>Whenever I try to extend a ruby module, I lose the module methods.  Neither include nor extend will do this.  Consider the snippet:</p>
  
  <pre><code>module A 
    def self.say_hi
      puts "hi"
    end
  end
  
  module B 
    include A
  end
  
  B.say_hi  #undefined_method
  </code></pre>
  
  <p>Whether B Includes or Extends A, say_hi will not be defined.  </p>
  
  <p>Is there any way to accomplish something like this?</p>