code: def contrast(im, contrast_lower, contrast_upper):
      contrast_delta = np.random.uniform(contrast_lower, contrast_upper)
      im = ImageEnhance.Contrast(im).enhance(contrast_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 10 for calling a global function with example usage: contrast(im, contrast_lower, contrast_upper) and returns: im