In Mutex.aquire why do we need to throw InterruptedException

It is a copy and paste from Doug Lea's Mutex implementation. I dont
understand the point of this line:
    if (Thread.interrupted()) throw new InterruptedException();


  public void acquire() throws InterruptedException {
    if (Thread.interrupted()) throw new InterruptedException();
    synchronized(this) {
      try {
        while (inuse_) wait();
        inuse_ = true;
      }
      catch (InterruptedException ex) {
        notify();
        throw ex;
      }
    }
  }


Thx