code: def load_env(self):
          
          for key, value in self.spec.items():
              if value['type'] in (dict, list):
                  envar = (self.env_prefix + "_" + key).upper()
                  try:
                      envvar = env.json(envar,
                                        default=getattr(self, key.upper(), value.get('default')))
                  except ConfigurationError as _err:  #pragma: no cover
                      print(_err)
                      self.log.critical(f"Error parsing json from env var. {os.environ.get(envar)}")
                      print(envar)
                      raise
              else:
                  envvar = env((self.env_prefix + "_" + key).upper(),
                               default=getattr(self, key.upper(), value.get('default')),
                               cast=value['type'])
              setattr(self, key.upper(), envvar)
docs: Load the model fron environment variables