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: zonefile.rb
    path of file: ./repos/GloboDNS/lib
    
    the code of the file until where you have to start completion: # Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NO
    
  def self.simplify(zf)
    zf.gsub(/("(""|[^"])*")|;.*$/, '\1') # strip comments (unless the ; is inside quotes)
    .gsub(/\r/, '')                    # strip carriage return characters
    .gsub(/\n+\s*\n+/, "\n")           # strip blank lines
    .gsub(/(\(.*?\))/m) {              # join content split into multiple lines using parentheses
                                       $1.gsub(/\s+/, ' ')
                                       }.strip                            # remove trailing whitespace
  end