class_docstr: Compose several preprocess together.
  Args:
      preprocess (list of ``Preprocess`` objects): list of preprocess to compose.
code: def __repr__(self):
      format_string = self.__class__.__name__ + "("
      for t in self.preprocess:
          format_string += "\n"
          format_string += "    {0}".format(t)
      format_string += "\n)"
      return format_string
  
imports: import random
  import cv2
  import numpy
  import torch
  from scipy import signal
label_desc: Use image node_id 3 for calling the Compose obj's underlying member method code with example usage: obj.__repr__() and returns: format_string