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: mirror_probe_spec.rb
    path of file: ./repos/ruby-packer/ruby/spec/bundler/realworld
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require_relative "../support/silent_logger"

RSpec.describe "fetching dependencies with a not available mirror", :realworld => true do
  let(:mirror) { @mirror_uri }
  let(:original) { @server_uri }
  let(:server_port) { @server_port }
  let(:host) { "127.0.0.1" }

  before do
    require_rack
    setup_server
    setup_mirror
  end

  after do
    Artifice.d
    
  def setup_server
    @server_port = find_unused_port
    @server_uri = "http://#{host}:#{@server_port}"

    require_relative "../support/artifice/endpoint"

    @server_thread = Thread.new do
      Rack::Server.start(:app       => Endpoint,
                         :Host      => host,
                         :Port      => @server_port,
                         :server    => "webrick",
                         :AccessLog => [],
                         :Logger    => Spec::SilentLogger.new)
    end.run

    wait_for_server(host, @server_port)
  end

  def setup_mirror
    mirror_port = find_unused_port
    @mirror_uri = "http://#{host}:#{mirror_port}"
  end
end