You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: module_function_spec.rb
    path of file: ./repos/artichoke/spec-runner/vendor/spec/core/module
    
    the code of the file until where you have to start completion: require_relative '../../spec_helper'
require_relative 'fixtures/classes'

describe "Module#module_function" do
  it "is a private method" do
    Module.should have_private_instance_method(:module_function)
  end

  describe "on Class" do
    it "is undefined" do
      Class.should_not have_private_instance_method(:module_function, true)
    end

    it "raises a TypeError if calling after re
    
      def test()  end
      def test2() end
      def test3() end

      module_function :test, :test2
    end

    m.respond_to?(:test).should == true
    m.respond_to?(:test2).should == true
    m.respond_to?(:test3).should == false
  end

  it "returns the current module" do
    x = nil
    m = Module.new do
      def test()  end
      x = module_function :test
    end

    x.should == m
  end

  it "creates an independent copy of the method, not a redirect" do
    module Mixin
      def test
        "hello"
      end
      module_function :test
    end

    class BaseClass
      include Mixin
      def call_test
        test
      end
    end

    Mixin.test.should == "hello"
    c = BaseClass.new
    c.call_test.should == "hello"

    module Mixin
      def test
        "goodbye"
      end
    end