class_docstr: Base class for similarity explainers.
docstr: Adds batch dimension.
docstr_tok: ["Adds","batch","dimension","."]
code: def _format(
      x: "Union[np.ndarray, tensorflow.Tensor, torch.Tensor, Any]",
  ) -> "Union[np.ndarray, tensorflow.Tensor, torch.Tensor, List[Any]]":
      """Adds batch dimension."""
      if BaseSimilarityExplainer._is_tensor(x):
          return x[None]
      return [x]
  
imports: from abc import ABC
  from typing import TYPE_CHECKING, Any, Callable, List, Optional, Union
  import numpy
  from alibi.api.interfaces import Explainer
  from alibi.explainers.similarity.backends import _select_backend
  from alibi.utils.frameworks import Framework, has_pytorch, has_tensorflow
  from alibi.utils.missing_optional_dependency import import_optional
  from tqdm import tqdm
  from typing_extensions import Literal
label_desc: Use image node_id 4 for calling the BaseSimilarityExplainer obj's underlying member method code with example usage: obj._format(x) and returns: list, x