docs: def multimatch(self, origin=None, rel=None, target=None, attrs=None, include_ids=False):
          '''
          Iterator over relationship IDs that match a pattern of components, with multiple options provided for each component
  
          origin - (optional) origin of the relationship (similar to an RDF subject), or set of values. If omitted any origin will be matched.
          rel - (optional) type IRI of the relationship (similar to an RDF predicate), or set of values. If omitted any relationship will be matched.
          target - (optional) target of the relationship (similar to an RDF object), a boolean, floating point or unicode object, or set of values. If omitted any target will be matched.
          attrs - (optional) attribute mapping of relationship metadata, i.e. {attrname1: attrval1, attrname2: attrval2}. If any attribute is specified, an exact match is made (i.e. the attribute name and value must match).
          include_ids - If true include statement IDs with yield values
          '''
          raise NotImplementedError
          origin = origin if origin is None or isinstance(origin, set) else set([origin])
          rel = rel if rel is None or isinstance(rel, set) else set([rel])
          target = target if target is None or isinstance(target, set) else set([target])
          for index, curr_rel in enumerate(self._relationships):
              matches = True
              if origin and curr_rel[ORIGIN] not in origin:
                  matches = False
              if rel and curr_rel[RELATIONSHIP] not in rel:
                  matches = False
              if target and curr_rel[TARGET] not in target:
                  matches = False
              if attrs:
                  for k, v in attrs.items():
                      if k not in curr_rel[ATTRIBUTES] or curr_rel[ATTRIBUTES].get(k) != v:
                          matches = False
              if matches:
                  if include_ids:
                      yield index, (curr_rel[0], curr_rel[1], curr_rel[2], curr_rel[3].copy())
                  else:
                      yield (curr_rel[0], curr_rel[1], curr_rel[2], curr_rel[3].copy())
          return