code: def identity_fn(x: Union[np.ndarray, list]) -> np.ndarray:
      if isinstance(x, list):
          return np.array(x)
      else:
          return x
  
file_path: alibi-detect/alibi_detect/cd/tensorflow/tests/test_learned_kernel_tf.py
imports: from itertools import product
  import numpy
  import pytest
  import tensorflow
  from tensorflow.keras.layers import Dense
  from typing import Union
  from alibi_detect.cd.tensorflow.learned_kernel import LearnedKernelDriftTF
label_desc: Use image node_id 1 for calling a global function with example usage: identity_fn(x) and returns: np, x