execute (Rake::RemoteTask::Action)

    # File lib/rake_remote_task.rb, line 551
        def execute hosts, args = nil
          hosts.each do |host|
            t = task.clone
            t.target_host = host
            thread = Thread.new(t) do |task|
              Thread.current[:task] = task
              block.call args
            end
            @workers << thread
          end
          @workers.each { |w| w.join }
        end