code: def valid_seed(cls, v):
      if v is not None and v < 0:
          raise ValidationError("`seed` must be positive")
      return v
  
imports: from enum import Enum
  from pydantic import BaseModel, validator
  from typing import Optional, List
  from text_generation.errors import ValidationError
label_desc: Use image node_id 3 for calling the Parameters obj's underlying member method code with example usage: obj.valid_seed(cls, v) and returns: v