docs: function() {
          var args = [].slice.call(arguments, 0);
          var workerMessage, done = 0;
          var workerKeys = Object.keys(cluster.workers);
          var nextWorker = function() {
            if (workerKeys.length) {
              done++;
              cluster.workers[workerKeys.shift()].send(taskMessage.concat([args]));
            } else {
              app.log("Executed [%s] on %d workers", id, done);
              app.removeListener('worker_message', workerMessage);
            }
          }
          app.on('worker_message', workerMessage = function(msg) {
            if (isMessageForMe(msg) && msg[3] === 'done') {
              nextWorker()
            }
          });
          nextWorker();
        }