def apply_annotation(self, bo, annotation):
<EOL>if not isinstance(annotation, RegionAnnotation):<EOL><INDENT>return bo<EOL><DEDENT>if not isinstance(bo, ValueSet):<EOL><INDENT>bo = ValueSet.empty(bo.bits)<EOL><DEDENT>return bo.apply_annotation(annotation)<EOL>
Apply an annotation on the backend object.

:param BackendObject bo: The backend object.
:param Annotation annotation: The annotation to be applied
:return: A new BackendObject
:rtype: BackendObject