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_gem_available_set.rb
    path of file: ./repos/rubygems/test/rubygems
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require_relative "helper"
require "rubygems/available_set"
require "rubygems/security"

class TestGemAvailableSet < Gem::TestCase
  def setup
    super

    @source = Gem::Source.new(@gem_repo)
  end

  def test_add_and_empty
    a1, _ = util_gem "a", "1"

    set = Gem::AvailableSet.new
    assert set.empty?

    
    
  def test_sorted_respect_pre
    a1a, _ = util_gem "a", "1.a"
    a1,  _ = util_gem "a", "1"
    a2a, _ = util_gem "a", "2.a"
    a2,  _ = util_gem "a", "2"
    a3a, _ = util_gem "a", "3.a"

    set = Gem::AvailableSet.new
    set.add a1, @source
    set.add a1a, @source
    set.add a3a, @source
    set.add a2a, @source
    set.add a2, @source

    g = set.sorted.map(&:spec)

    assert_equal [a3a, a2, a2a, a1, a1a], g
  end