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: proguard.rb
    path of file: ./repos/homebrew-core/Formula/p
    
    the code of the file until where you have to start completion: class Proguard < Formula
  desc "Java class file shrinker, optimizer, and obfuscator"
  homepag
    
  def install
    libexec.install "lib/proguard.jar"
    libexec.install "lib/proguardgui.jar"
    libexec.install "lib/retrace.jar"
    bin.write_jar_script libexec/"proguard.jar", "proguard"
    bin.write_jar_script libexec/"proguardgui.jar", "proguardgui"
    bin.write_jar_script libexec/"retrace.jar", "retrace"
  end