ruby module里的self

class SampleClass
    def self.class_method1 # 类方法定义 1
        ...
    end

    class << SampleClass # 类方法定义 2
        def class_method2
            ...
        end
    end
end

module SampleModule
  extend ActiveSupport::Concern
  SampleModuleSelector = [
    :sayHello,
    :sayGoodbye
  ]

  included do
  end

  def runner
    self.send SampleModuleSelector[0]
    self.send SampleModuleSelector[1]
  end

  private
    def sayHello
      puts %Q(UUID sayHello)
    end

    def sayGoodbye
      puts %Q(UUID sayGoodbye)
    end
end