src/main/java/io/arivera/oss/embedded/rabbitmq/apache/commons/lang3/StopWatch.java
public void start() {
    if (this.runningState == State.STOPPED) {
      throw new IllegalStateException("Stopwatch must be reset before being restarted. ");
    }
    if (this.runningState != State.UNSTARTED) {
      throw new IllegalStateException("Stopwatch already started. ");
    }
    this.startTime = System.nanoTime();
    this.startTimeMillis = System.currentTimeMillis();
    this.runningState = State.RUNNING;
  }
public void start() {
    if (this.runningState == State.STOPPED) {
      throw new IllegalStateException("Stopwatch must be reset before being restarted. ");
    }
    if (this.runningState != State.UNSTARTED) {
      throw new IllegalStateException("Stopwatch already started. ");
    }
    this.startTime = System.nanoTime();
    this.startTimeMillis = System.currentTimeMillis();
    this.runningState = State.RUNNING;
  }
<p>
Start the stopwatch.
</p>

<p>
This method starts a new timing session, clearing any previous values.
</p>

@throws IllegalStateException
if the StopWatch is already running.