code: public void start(String taskName) throws IllegalStateException {
          this.lastTaskInfo = new TaskInfo(taskName, System.currentTimeMillis());
          this.runningTasks.push(lastTaskInfo);
          ++this.taskCount;
          this.running = true;
          this.currentTaskName = taskName;
      }
docs: Start a named task. The results are undefined if {@link #stop()}
  or timing methods are called without invoking this method.
  @param taskName the name of the task to start
  @see #stop()