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: test_wait.rb
    path of file: ./repos/truffleruby/test/mri/tests/cext-ruby/wait
    
    the code of the file until where you have to start completion: # frozen_string_literal: false
r
    
  def test_wait_for_closed_pipe
    IO.pipe do |r,w|
      w.close
      rc = IO.io_wait(r, IO::READABLE, nil)
      assert_equal IO::READABLE, rc
    end
  end