public GenericDraweeHierarchyBuilder setProgressBarImage(@Nullable Drawable progressBarDrawable) {
    mProgressBarImage = progressBarDrawable;
    return this;
  }
Sets the progress bar image.

@param progressBarDrawable drawable to be used as progress bar image
@return modified instance of this builder
drawee/src/main/java/com/facebook/drawee/generic/GenericDraweeHierarchyBuilder.java