class_docstr: A protocol for strategies to be used for typing mixin classes.
code: def backward(self) -> None:
      ...
  
imports: from typing import Iterable, List, Optional, Sequence, Tuple, TypeVar
  from typing_extensions import Protocol
  from torch import Tensor
  import torch
  from torch.optim.optimizer import Optimizer
  from torch.nn import Module
  from avalanche.benchmarks.scenarios.generic_scenario import CLExperience
  from avalanche.benchmarks import DatasetExperience
  from avalanche.core import BasePlugin
label_desc: Use image node_id 3 for calling the SGDStrategyProtocol obj's underlying member method code with example usage: obj.backward() without return types