code: def update_last_wm_layers(self, service_id, num_layers=10):
      
      from hypermap.aggregator.models import Service
  
      LOGGER.debug(
          'Updating the index the last %s added and %s deleted layers in WorldMap service'
          % (num_layers, num_layers)
                  )
      service = Service.objects.get(id=service_id)
      # TODO raise error if service type is not WM type
      if service.type == 'Hypermap:WorldMapLegacy':
          from hypermap.aggregator.models import update_layers_wm_legacy as update_layers_wm
      if service.type == 'Hypermap:WorldMap':
          from hypermap.aggregator.models import update_layers_geonode_wm as update_layers_wm
  
      update_layers_wm(service, num_layers)
  
      # Remove in search engine last num_layers that were deleted
      LOGGER.debug('Removing the index for the last %s deleted layers' % num_layers)
      layer_to_unindex = service.layer_set.filter(was_deleted=True).order_by('-last_updated')[0:num_layers]
      for layer in layer_to_unindex:
          if not settings.REGISTRY_SKIP_CELERY:
              unindex_layer(layer.id, use_cache=True)
          else:
              unindex_layer(layer.id)
  
      # Add/Update in search engine last num_layers that were added
      LOGGER.debug('Adding/Updating the index for the last %s added layers' % num_layers)
      layer_to_index = service.layer_set.filter(was_deleted=False).order_by('-last_updated')[0:num_layers]
      for layer in layer_to_index:
          if not settings.REGISTRY_SKIP_CELERY:
              index_layer(layer.id, use_cache=True)
          else:
              index_layer(layer.id)
docs: Update and index the last added and deleted layers (num_layers) in WorldMap service.