class_docstr: Base class for similarity explainers.
docstr: Checks if an obejct is a tensor.
docstr_tok: ["Checks","if","an","obejct","is","a","tensor","."]
code: def _is_tensor(x: Any) -> bool:
      """Checks if an obejct is a tensor."""
      if has_tensorflow and isinstance(x, _TfTensor):
          return True
      if has_pytorch and isinstance(x, _PtTensor):
          return True
      if isinstance(x, np.ndarray):
          return True
      return False
  
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 3 for calling the BaseSimilarityExplainer obj's underlying member method code with example usage: obj._is_tensor(x) and returns: False, True, True, True