    # File lib/chef/checksum_cache.rb, line 80
        def self.cleanup_checksum_cache
          Chef::Log.debug("Cleaning the checksum cache")
          if (Chef::Config[:cache_type].to_s == "BasicFile")
            all_cached_checksums.each do |cache_key, cksum_cache_file|
              unless valid_cached_checksums.include?(cache_key)
                remove_unused_checksum(cksum_cache_file)
              end
            end
          end
        end