code: def __init__(self, pipeline, module, callback):
      """Initialize the validation request
  
      pipeline - pipeline in question
      module - module in question
      callback - call this callback if there is an error. Do it on the GUI thread
      """
      self.pipeline = pipeline
      self.module_num = module.module_num
      self.test_mode = pipeline.test_mode
      self.callback = callback
      self.cancelled = False
  
label_desc: Use image node_id 1 to create a new ValidationRequestController object  with example: obj = ValidationRequestController(pipeline, module, callback)