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_io_buffer.rb
    path of file: ./repos/jruby/test/mri/fiber
    
    the code of the file until where you have to start completion: # frozen_string_literal: true
require 'test/unit'
require_relative 'scheduler'

require 'timeout'

class TestFiberIOBuffer < Test::Unit::TestCase
  MESSAGE = "Hello W
    
  def test_timeout_after
    skip "UNIXSocket is not defined!" unless defined?(UNIXSocket)

    i, o = UNIXSocket.pair
    i.nonblock = false
    o.nonblock = false

    message = nil
    error = nil

    thread = Thread.new do
      scheduler = IOBufferScheduler.new
      Fiber.set_scheduler scheduler

      Fiber.schedule do
        Timeout.timeout(0.1) do
          message = i.read(20)
        end
      rescue Timeout::Error => error
        # Assertions below.
      ensure
        i.close
      end
    end

    thread.join

    assert_nil message
    assert_kind_of Timeout::Error, error
  ensure
    i&.close
    o&.close
  end