code: def is_valid(cls, lifecycle_stage):
      return lifecycle_stage in cls._VALID_STAGES
  
imports: from mlflow.entities.view_type import ViewType
  from mlflow.exceptions import MlflowException
label_desc: Use image node_id 2 for calling the LifecycleStage obj's underlying member method code with example usage: obj.is_valid(cls, lifecycle_stage) and returns: unknown