protected void updateDebugOverlay(
      @Nullable CloseableImage image, DebugControllerOverlayDrawable debugOverlay) {
    debugOverlay.setControllerId(getId());

    final DraweeHierarchy draweeHierarchy = getHierarchy();
    ScaleType scaleType = null;
    if (draweeHierarchy != null) {
      final ScaleTypeDrawable scaleTypeDrawable =
          getActiveScaleTypeDrawable(draweeHierarchy.getTopLevelDrawable());
      scaleType = scaleTypeDrawable != null ? scaleTypeDrawable.getScaleType() : null;
    }
    debugOverlay.setScaleType(scaleType);

    String callerContextString = getCallerContextString();
    if (callerContextString != null) {
      debugOverlay.addAdditionalData("cc", callerContextString);
    }

    if (image != null) {
      debugOverlay.setDimensions(image.getWidth(), image.getHeight());
      debugOverlay.setImageSize(image.getSizeInBytes());
    } else {
      debugOverlay.reset();
    }
  }
updateDebugOverlay updates the debug overlay. Subclasses of {@link PipelineDraweeController}
can override this method (and call <code>super</code>) to provide additional debug information.
drawee-backends/drawee-pipeline/src/main/java/com/facebook/drawee/backends/pipeline/PipelineDraweeController.java