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: ren.rb
    path of file: ./repos/homebrew-core/Formula/r
    
    the code of the file until where you have to start completion: class Ren < Formula
  desc "Rename multiple files
    
  def install
    # Fix compile with newer Clang
    ENV.append_to_cflags "-Wno-implicit-function-declaration" if DevelopmentTools.clang_build_version >= 1403

    system "make"
    bin.install "ren"
    man1.install "ren.1"
  end