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: util_test.rb
    path of file: ./repos/stackneveroverflow/vendor/bundle/ruby/2.3.0/gems/haml-5.0.1/test
    
    the code of the file until where you have to start completion: require 'test_helper'

class UtilTest < Haml::TestCase
  include Haml::Util

  def test_sil
    
  def test_silence_warnings
    old_stderr, $stderr = $stderr, StringIO.new
    warn "Out"
    assert_equal("Out\n", $stderr.string)
    silence_warnings {warn "In"}
    assert_equal("Out\n", $stderr.string)
  ensure
    $stderr = old_stderr
  end