code: def _models(self, appname):
          
          try:
              app = self._get_app(appname)
          except Exception as e:
              self.err("Can not get app " + appname, e)
              return
          if appname not in self.appnames:
              self.err("App " + appname + " not found in settings")
              return
          models = self._get_models(app)
          return models
docs: return models_array