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_stringscanner.rb
    path of file: ./repos/ruby/test/strscan
    
    the code of the file until where you have to start completion: # -*- coding: utf-8 -*-
# frozen_string_literal: true
#
# test/strscan/test_stringscanner.rb
#

require 'strscan'
require 'test/unit'

module StringScannerTests
  def test_peek_byte
    s
    
  def test_charpos_not_use_string_methods
    omit "not supported on TruffleRuby" if RUBY_ENGINE == "truffleruby"

    string = +'abcädeföghi'
    scanner = create_string_scanner(string)

    class << string
      EnvUtil.suppress_warning do
        undef_method(*instance_methods)
      end
    end