ruby: include class and instance methods from single module

include.rb

module SomeModule
  # instance methods:
  def some_instance_method
    # do something here
  end
  
  # module, which contains class methods
  module ClassMethods
    # class methods:
    def some_class_method
      # do something
    end
  end
  
  # included method is invoked every time module is included
  # in this case included is invoked, when SomeModule is included
  def self.included(base)
    base.extend(ClassMethods)
  end
end

class SomeClass
  include SomeModule
  # now, methods from SomeModule are available in SomeClass and its instances
end

SomeClass.new.some_instance_method
SomeClass.some_class_method