code: public void start(String taskName) throws IllegalStateException {
  		if (this.running) {
  			throw new IllegalStateException("Can't start StopWatch: it's already running");
  		}
  		this.startTimeMillis = System.currentTimeMillis();
  		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()