docs: def getOr(subject, predicate, *args, **kwargs):
          """ Retrieve a metadata node or generate a new one
  
          :param subject: Subject to which the metadata node should be connected
          :param predicate: Predicate by which the metadata node should be connected
          :return: Metadata for given node
          :rtype: Metadata
  
          """
          if (subject, predicate, None) in get_graph():
              return Metadata(node=get_graph().objects(subject, predicate).__next__())
          return Metadata(*args, **kwargs)