code: def squared_difference(a: np.array, b: np.array, **kwargs) -> float:
      """
      Calculate the sqaured differences between two images (or explanations).
  
      Parameters
      ----------
      a: np.ndarray
           The first array to use for similarity scoring.
      b: np.ndarray
           The second array to use for similarity scoring.
      kwargs: optional
          Keyword arguments.
  
      Returns
      -------
      float
          The similarity score.
      """
      return np.sum((a - b) ** 2)
  
file_path: Quantus/quantus/functions/similarity_func.py
imports: from typing import Union
  import numpy
  import scipy
  import skimage
label_desc: Use image node_id 9 for calling a global function with example usage: squared_difference(a, b) and returns: np