def path_to(hash = nil)
      @base_dir ||= File.join(Jekyll::Cache.cache_dir, @name)
      return @base_dir if hash.nil?

      File.join(@base_dir, hash[0..1], hash[2..-1]).freeze
    end
def path_to(hash = nil)
      @base_dir ||= File.join(Jekyll::Cache.cache_dir, @name)
      return @base_dir if hash.nil?

      File.join(@base_dir, hash[0..1], hash[2..-1]).freeze
    end
Given a hashed key, return the path to where this item would be saved on disk.