docs: def get_triples(self, subject=None, predicate=None, object_=None):
          """Returns triples that correspond to the specified subject,
          predicates, and objects."""
  
          for triple in self.triples:
  
              # Filter out non-matches
              if subject is not None and triple['subject'] != subject:
                  continue
              if predicate is not None and triple['predicate'] != predicate:
                  continue
              if object_ is not None and triple['object'] != object_:
                  continue
  
              yield triple