class_docstr: Wraps a mock image array and provide a needed getdata() interface function. 
code: def __init__(self, a):
      self.a = a
  
file_path: petastorm/examples/mnist/tests/conftest.py
imports: import numpy
  import pytest
label_desc: Use image node_id 1 to create a new MockDataObj object from inherited base classes: object with example: obj = MockDataObj(a)