code: def imread(filename):
      ''' 
      Like cv2.imread
      This function will make sure filename exists 
      '''
      im = cv2.imread(filename)
      if im is None:
          raise RuntimeError("file: '%s' not exists" % filename)
      return if imread(filename):
      ''' 
      Like cv2.imread
      This function will make sure filename exists 
      '''
      im = cv2.imread(filename)
      if im is None:
          raise RuntimeError("file: '%s' not exists" % filename)
      return im
docs: Like cv2.imread
      This function will make sure filename exists