code: def _handle_start_relation(self, attrs):
          
          self._curr = {
              'attributes': dict(attrs),
              'members': [],
              'rel_id': None,
              'tags': {}
          }
          if attrs.get('id', None) is not None:
              self._curr['rel_id'] = int(attrs['id'])
              del self._curr['attributes']['id']
docs: Handle opening relation element
  
          :param attrs: Attributes of the element
          :type attrs: Dict