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: exim.rb
    path of file: ./repos/homebrew-core/Formula/e
    
    the code of the file until where you have to start completion: class Exim < Formula
  desc "Complete replacement for sendmail"
  homepage "https://exim.org"
  url "https://ftp.exim.org/pub/exim/exim4/exim-4.97.1.tar.xz"
  sha256 "bd782057509a793593508528590626d185ea160ce32cb34beda262e99cefdfa9"
  license "GPL-2.0-or-later"

  # Maintenance releases are kept in a `fixes` subdirectory, so it's necessary
  # to check both the main `exim4` directory and the `fixes` subdirectory to
  # identify the latest version.
  livecheck do
    url "https://ftp.exim.org/pub/exim/exim4/"
    regex(/href=.*?exim[._-]v?(\d+(?:\.\d+)+)\.t/i)
    strategy :page_match do |page, regex|
      # Match versions from files in the `exim4` directory
      versions = page.scan(regex).flatten.uniq

      # Return versions if a `fixes` subdirectory isn't present
      next versions if page.match(%r{href=["']?fixes/?["' >]}i).blank?

      # Fetch the page for the `fixes` directory
      fixes_page = Homebrew::Livecheck::Strategy.page_content(URI.join(@url, "fixes").to_s)
      next versions if fixes_page[:content].blank?

      # Match 
    
  def install
    # fix `Cannot read timezone file /usr/share/zoneinfo/UTC0` issue
    ENV["TZ"] = "UTC"

    ENV.prepend_create_path "PERL5LIB", libexec/"lib/perl5"
    inreplace "OS/Makefile-Default", "/usr/bin/perl", Formula["perl"].opt_bin/"perl" if OS.linux?

    resources.each do |r|
      r.stage do
        system "perl", "Makefile.PL", "INSTALL_BASE=#{libexec}"
        system "make", "install"
      end
    end

    cp "src/EDITME", "Local/Makefile"
    inreplace "Local/Makefile" do |s|
      s.change_make_var! "EXIM_USER", ENV["USER"]
      s.change_make_var! "SYSTEM_ALIASES_FILE", etc/"aliases"
      s.gsub! "/usr/exim/configure", etc/"exim.conf"
      s.gsub! "/usr/exim", prefix
      s.gsub! "/var/spool/exim", var/"spool/exim"
      # https://trac.macports.org/ticket/38654
      s.gsub! 'TMPDIR="/tmp"', "TMPDIR=/tmp"
    end
    open("Local/Makefile", "a") do |s|
      s << "AUTH_PLAINTEXT=yes\n"
      s << "SUPPORT_TLS=yes\n"
      s << "USE_OPENSSL=yes\n"
      s << "TLS_LIBS=-lssl -lcrypto\n"
      s << "TRANSPORT_LMTP=yes\n"

      # For non-/usr/local HOMEBREW_PREFIX
      s << "LOOKUP_INCLUDE=-I#{HOMEBREW_PREFIX}/include\n"
      s << "LOOKUP_LIBS=-L#{HOMEBREW_PREFIX}/lib\n"
    end

    bdb5 = Formula["berkeley-db@5"]

    cp "OS/unsupported/Makefile-Darwin", "OS/Makefile-Darwin"
    cp "OS/unsupported/os.h-Darwin", "OS/os.h-Darwin"
    inreplace "OS/Makefile-Darwin" do |s|
      s.remove_make_var! %w[CC CFLAGS]
      # Add include and lib paths for BDB 5
      s.gsub! "# Exim: OS-specific make file for Darwin (Mac OS X).", "INCLUDE=-I#{bdb5.include}"
      s.gsub! "DBMLIB =", "DBMLIB=#{bdb5.lib}/libdb-5.dylib"
    end

    # The compile script ignores CPPFLAGS
    ENV.append "CFLAGS", ENV.cppflags

    ENV.deparallelize # See: https://lists.exim.org/lurker/thread/20111109.083524.87c96d9b.en.html
    system "make"
    system "make", "INSTALL_ARG=-no_chown", "install"
    man8.install "doc/exim.8"
    (bin/"exim_ctl").write startup_script
  end