class_docstr: Mocks the `open` built-in function. A call to the instance of OpenMock returns an in-memory file which is
  readable and writable. The actual in-memory file implementation should call the passed `save_value` method
  to save the file content in the cache when the file is being closed to preserve the file content.
code: def __init__(self):
      self.values = {}
  
imports: import inspect
  import random
  import typing
  from io import StringIO
  from typing import Optional, Set, Type
  import numpy
  import albumentations
label_desc: Use image node_id 1 to create a new OpenMock object  with example: obj = OpenMock()