# File lib/hammer_cli_import/asynctasksreactor.rb, line 61
      def postpone_till(uuids, &block)
        if option_no_async?
          wait_for uuids, &block
          return
        end
        if uuids.empty?
          info 'Nothing to wait for, running in main thread.'
          block.call
          return
        end
        info "Registering tasks for uuids: #{uuids.inspect}."
        uuids.sort!
        @queue.enq([uuids, block])
        start_async_task_thread
        nil
      end