code: def saturation(im, saturation_lower, saturation_upper):
      saturation_delta = np.random.uniform(
          saturation_lower, saturation_upper
      )
      im = ImageEnhance.Color(im).enhance(saturation_delta)
      return im
  
imports: import cv2
  import numpy
  from PIL import Image, ImageEnhance
  from scipy.ndimage import distance_transform_edt
label_desc: Use image node_id 11 for calling a global function with example usage: saturation(im, saturation_lower, saturation_upper) and returns: im