code: public function start($taskName, $repeat = null)
      {
          $task = new Task();
          $task->name($taskName);
          if ($repeat) {
              $task->repeat($repeat);
          }
          if (isset($this->_tasks[$taskName])) {
              throw new Exception("Task {$taskName} is already defined.");
          }
          $this->_tasks[$taskName] = $task;
          $task->start();
          return $task;
      }
docs: Starts the timer for a task
  
  @param  string  $taskName The taskname to start.
  @param  integer $repeat   The number of times the task will be executed.
  @return object            The started task.