code: def update_layers(self):
          
  
          signals.post_save.disconnect(layer_post_save, sender=Layer)
  
          try:
              LOGGER.debug('Updating layers for service id %s' % self.id)
              if self.type == 'OGC:WMS':
                  update_layers_wms(self)
              elif self.type == 'OGC:WMTS':
                  update_layers_wmts(self)
              elif self.type == 'ESRI:ArcGIS:MapServer':
                  update_layers_esri_mapserver(self)
              elif self.type == 'ESRI:ArcGIS:ImageServer':
                  update_layers_esri_imageserver(self)
              elif self.type == 'Hypermap:WorldMapLegacy':
                  update_layers_wm_legacy(self)
              elif self.type == 'Hypermap:WorldMap':
                  update_layers_geonode_wm(self)
              elif self.type == 'Hypermap:WARPER':
                  update_layers_warper(self)
  
          except:
              LOGGER.error('Error updating layers for service %s' % self.uuid)
  
          signals.post_save.connect(layer_post_save, sender=Layer)
docs: Update layers for a service.