code: def no_perturbation(arr: np.array, **kwargs) -> np.array:
      """
      Apply no perturbation to input.
  
      Parameters
      ----------
      arr: np.ndarray
           Array to be perturbed.
      kwargs: optional
          Keyword arguments.
  
      Returns
      -------
      arr: np.ndarray
           Array unperturbed.
      """
      return arr
  
file_path: Quantus/quantus/functions/perturb_func.py
imports: import copy
  import random
  import warnings
  from typing import Any, Callable, Sequence, Tuple, Union, Optional
  import cv2
  import numpy
  from scipy.sparse import lil_matrix, csc_matrix
  from scipy.sparse.linalg import spsolve
  from quantus.helpers.utils import get_baseline_value, blur_at_indices, expand_indices, get_leftover_shape, offset_coordinates
label_desc: Use image node_id 11 for calling a global function with example usage: no_perturbation(arr) and returns: arr