code: public static List<Webcam> getWebcams(long timeout) throws TimeoutException, WebcamException {
  		if (timeout < 0) {
  			throw new IllegalArgumentException(String.format("Timeout cannot be negative (%d)", timeout));
  		}
  		return getWebcams(timeout, TimeUnit.MILLISECONDS);
  	}
docs: Get list of webcams to use. This method will wait given time interval for webcam devices to
  be discovered. Time argument is given in milliseconds.
  
  @param timeout the time to wait for webcam devices to be discovered
  @return List of webcams existing in the ssytem
  @throws TimeoutException when timeout occurs
  @throws WebcamException when something is wrong
  @throws IllegalArgumentException when timeout is negative
  @see Webcam#getWebcams(long, TimeUnit)