code: function (input) {
              if (typeof input !== 'undefined' && input !== null && input !== false) {
                  master.emit('input', input, for_worker);
              } else {
  
                  //No input? We might be done..
  
                  var isComplete = function () {
                      //Check if any input was added dynamically
                      if (job.input.length > 0) {
                          job.is_complete = false;
                          return false;
                      }
  
                      //Wait for workers or instances that are still working
                      return worker_count > 0 ? areWorkersComplete() : job.instances <= 0;
                  };
  
                  //If we're not complete, check periodically
                  if (isComplete()) {
                      master.emit('complete');
                  } else {
                      completeCheckInterval = setInterval(function () {
                          if (isComplete()) {
                              clearInterval(completeCheckInterval);
                              master.emit('complete');
                          }
                      }, 300);
                  }
              }
          }
docs: Callback for when input is received from job.input()