code: def _get_feature_map(
      self, dim_input: int, dim_features: int, device: torch.device
  ):
      raise NotImplementedError()
  
file_path: xformers/xformers/components/attention/feature_maps/base.py
imports: from abc import abstractmethod
  from dataclasses import asdict, dataclass
  from typing import Optional, Type, TypeVar
  import torch
label_desc: Use image node_id 2 for calling the FeatureMap obj's underlying member method code with example usage: obj._get_feature_map(dim_input, dim_features, device) without return types