code: def _parse_trunk_groups(self, config):
          
          values = TRUNK_GROUP_RE.findall(config)
          return dict(trunk_groups=values)
docs: _parse_trunk_groups scans the provided configuration block and
          extracts all the vlan trunk groups.  If no trunk groups are configured
          an empty List is returned as the vlaue.  The return dict is intended
          to be merged into the response dict.
  
          Args:
              config (str): The vlan configuration block form the node's
                  running configuration
  
          Returns:
              dict: resource dict attribute