# File lib/cft.rb, line 67
        def path(entry = nil)
            path = File::join(@session_dir, name)
            unless File::directory?(path)
                FileUtils::mkdir_p(path)
            end
            unless entry.nil? || entry == :top
                sub = PATHS[entry]
                if sub.nil?
                    raise InternalError, "Invalid session path #{entry}"
                end
                path = File::join(path, sub)
            end
            return path
        end