code: public ScreenshotState verifyChanged(Duration timeout, double minScore) {
          return checkState((x) -> x < minScore, timeout);
      }
docs: Verifies whether the state of the screenshot provided by stateProvider lambda function
  is changed within the given timeout.
  
  @param timeout  timeout value
  @param minScore the value in range (0.0, 1.0)
  @return self instance for chaining
  @throws ScreenshotComparisonTimeout if the calculated score is still
  greater or equal to the given score after timeout happens
  @throws ScreenshotComparisonError   if {@link #remember()} method has not been invoked yet