class_docstr: Adds a dummy channel to an image, also known as expanding an axis or unsqueezing a dim
  This will make an image of size (28, 28) to now be
  of size (1, 28, 28), for example.
  
  param axis: (int): dimension to be expanded to singleton
code: def __init__(self, axis=0):
      self.axis = axis
  
imports: import os
  import random
  import math
  import numpy
  import torch
label_desc: Use image node_id 1 to create a new AddChannel object  with example: obj = AddChannel(axis)