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: zero-install.rb
    path of file: ./repos/homebrew-core/Formula/z
    
    the code of the file until where you have to start completion: class ZeroInstall < Formula
  desc "Decentralised cross-platform software installation system"
  homepage "https://0install.net/"
  url "https://github.com/0install/0install.git",
      tag:      "v2.18",
      revision: "b58af5db6afd496cfd4a5f85fb23f30ba8dfbc87"
  li
    
  def install
    ENV.append_path "PATH", Formula["gnupg"].opt_bin

    Dir.mktmpdir("opamroot") do |opamroot|
      ENV["OPAMROOT"] = opamroot
      ENV["OPAMYES"] = "1"
      ENV["OPAMVERBOSE"] = "1"
      system "opam", "init", "--no-setup", "--disable-sandboxing"
      # Tell opam not to try to install external dependencies
      system "opam", "option", "depext=false"
      modules = %w[
        yojson
        xmlm
        ounit
        lwt_react
        ocurl
        sha
        dune
      ]
      system "opam", "config", "exec", "opam", "install", *modules

      # mkdir: <buildpath>/build: File exists.
      # https://github.com/0install/0install/issues/87
      ENV.deparallelize { system "opam", "config", "exec", "make" }

      inreplace "dist/install.sh" do |s|
        s.gsub! '"/usr/local"', prefix
        s.gsub! '"${PREFIX}/man"', man
      end
      system "make", "install"
    end
  end