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: json_index.rb
    path of file: ./repos/stackneveroverflow/vendor/bundle/ruby/2.3.0/gems/rdoc-4.3.0/lib/rdoc/generator
    
    the code of the file until where you have to start completion: require 'json'
begin
  require 'zlib'
rescue LoadError
end

##
# The JsonIndex generator is designed to complement an HTML generator and
# produces a JSON search index.  This generator is derived from sdoc by
# Vladimir Kolesnikov and contains verbatim code written by him.
#
# This generator is designed to be used with a regular HTML generator:
#
#   class RDoc::Generator::D
    
  def generate_gzipped
    return unless defined?(Zlib)

    debug_msg "Compressing generated JSON index"
    out_dir = @base_dir + @options.op_dir

    search_index_file = out_dir + SEARCH_INDEX_FILE
    outfile           = out_dir + "#{search_index_file}.gz"

    debug_msg "Reading the JSON index file from %s" % search_index_file
    search_index = search_index_file.read

    debug_msg "Writing gzipped search index to %s" % outfile

    Zlib::GzipWriter.open(outfile) do |gz|
      gz.mtime = File.mtime(search_index_file)
      gz.orig_name = search_index_file.basename.to_s
      gz.write search_index
      gz.close
    end

    # GZip the rest of the js files
    Dir.chdir @template_dir do
      Dir['**/*.js'].each do |source|
        dest = out_dir + source
        outfile = out_dir + "#{dest}.gz"

        debug_msg "Reading the original js file from %s" % dest
        data = dest.read

        debug_msg "Writing gzipped file to %s" % outfile

        Zlib::GzipWriter.open(outfile) do |gz|
          gz.mtime = File.mtime(dest)
          gz.orig_name = dest.basename.to_s
          gz.write data
          gz.close
        end
      end
    end
  end