code: def get_service_models(cls):
          
          from django.apps import apps
  
          data = {}
          for key, service in cls._registry.items():
              service_model = apps.get_model(service['model_name'])
              service_project_link = service_model.projects.through
              data[key] = {
                  'service': service_model,
                  'service_project_link': service_project_link,
                  'resources': [apps.get_model(r) for r in service['resources'].keys()],
                  'properties': [apps.get_model(r) for r in service['properties'].keys() if '.' in r],
              }
  
          return data
docs: Get a list of service models.
              {
                  ...
                  'gitlab': {
                      "service": nodeconductor_gitlab.models.GitLabService,
                      "service_project_link": nodeconductor_gitlab.models.GitLabServiceProjectLink,
                      "resources": [
                          nodeconductor_gitlab.models.Group,
                          nodeconductor_gitlab.models.Project
                      ],
                  },
                  ...
              }