code: def saturation_list(var, images):
      """
      Perform color saturation on the list of given images.
      Args:
          var (float): variance.
          images (list): list of images to perform color saturation.
      Returns:
          (list): list of images that performed color saturation.
      """
      alpha = 1.0 + np.random.uniform(-var, var)
  
      out_images = []
      for image in images:
          img_gray = grayscale(image)
          out_images.append(blend(image, img_gray, alpha))
      return out_images
  
imports: import math
  import numpy
  import cv2
label_desc: Use image node_id 28 for calling a global function with example usage: saturation_list(var, images) and returns: out_images