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: base.rb
    path of file: ./repos/artichoke/artichoke-backend/vendor/ruby/test/mkmf
    
    the code of the file until where you have to start completion: # frozen_string
    
  def teardown
    rbconfig0 = @rbconfig
    mkconfig0 = @mkconfig
    RbConfig.module_eval {
      remove_const(:CONFIG)
      const_set(:CONFIG, rbconfig0)
      remove_const(:MAKEFILE_CONFIG)
      const_set(:MAKEFILE_CONFIG, mkconfig0)
    }
    MakeMakefile.class_eval {
      remove_const(:CONFIG)
      const_set(:CONFIG, mkconfig0)
    }
    Logging.quiet = @quiet
    Logging.log_close
    FileUtils.rm_f("mkmf.log")
    Dir.chdir(@curdir)
    FileUtils.rm_rf(@tmpdir)
  end