code: def _handle_start_nd(self, attrs):
          
          if isinstance(self.cur_relation_member, RelationWay):
              if self.cur_relation_member.geometry is None:
                  self.cur_relation_member.geometry = []
              self.cur_relation_member.geometry.append(
                  RelationWayGeometryValue(
                      lat=Decimal(attrs["lat"]),
                      lon=Decimal(attrs["lon"])
                  )
              )
          else:
              try:
                  node_ref = attrs['ref']
              except KeyError:
                  raise ValueError("Unable to find required ref value.")
              self._curr['node_ids'].append(int(node_ref))
docs: Handle opening nd element
  
          :param attrs: Attributes of the element
          :type attrs: Dict