@ReturnsOwnership
  private static RoundingParams getRoundingParams(GenericDraweeHierarchyBuilder builder) {
    if (builder.getRoundingParams() == null) {
      builder.setRoundingParams(new RoundingParams());
    }
    return builder.getRoundingParams();
  }
Updates the existing hierarchy builder based on the XML attributes.

<p>This method is useful if a custom view uses different default values. In that case a builder
with adjusted default values can be passed to this method and only the properties explicitly
specified in XML will be overridden. The builder can be modified afterwards in case some XML
attributes needs to be overridden.

@param builder a hierarchy builder to be updated
@return the modified instance of the same builder
drawee/src/main/java/com/facebook/drawee/generic/GenericDraweeHierarchyInflater.java