@Override
  public String toString() {
    return Objects.toStringHelper(this)
        .add("super", super.toString())
        .add("dataSourceSupplier", mDataSourceSupplier)
        .toString();
  }
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