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: sass.rb
    path of file: ./repos/stackneveroverflow/vendor/bundle/ruby/2.3.0/gems/sass-3.4.24/lib
    
    the code of the file until where you have to start completion: dir = File.dirname(__FILE__)
$LOAD_PATH.unshift dir unless $LOAD_PATH.include?(dir)

require 'sass/version'

# The module that contains everything Sass-related:
#
# * {Sass::Engine} is
    
  def self.compile_file(filename, *args)
    options = args.last.is_a?(Hash) ? args.pop : {}
    css_filename = args.shift
    result = Sass::Engine.for_file(filename, options).render
    if css_filename
      options[:css_filename] ||= css_filename
      open(css_filename, "w") {|css_file| css_file.write(result)}
      nil
    else
      result
    end