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_sup-sync-back-maildir.rb
    path of file: ./repos/sup/test/integration
    
    the code of the file until where you have to start completion: require "test_helper"

class TestSupSyncBackMaildir < Minitest::Test

  def setup
    @path = Dir.mktmpdir

    @maildir = File.join @path, "test_maildir"
    Dir.mkdi
    
  def test_it_syncs_seen_unread_flags
    _out, _err = capture_subprocess_io do
      assert system({"SUP_BASE" => @path},
                    "bin/sup-tweak-labels",
                    "--all-sources",
                    "--add=replied",
                    "--remove=unread")
      assert system({"SUP_BASE" => @path}, "bin/sup-sync-back-maildir", "--no-confirm")
    end

    refute File.exist? (File.join @maildir, "new", "123.hostname")
    assert File.exist? (File.join @maildir, "cur", "123.hostname:2,RS")
  end