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: cache_store.rb
    path of file: ./repos/stackneveroverflow/vendor/bundle/ruby/2.3.0/gems/sass-rails-5.0.6/lib/sass/rails
    
    the code of the file until where you have to start completion: require 'sass'

module Sass
  module Rails
    class CacheStore < ::Sass::CacheStores::Base
      attr_reader :environment

      def initiali
    
      def _retrieve(key, version, sha)
        if obj = environment.cache_get("sass/#{key}")
          return unless obj[:version] == version
          return unless obj[:sha] == sha
          obj[:contents]
        else
          nil
        end