code: def __init__(self, loader, metrics):
      self.num_iterations = len(loader)
      self.output_stream = sys.stdout
      self.metrics = metrics
      self.alpha = 0.98
  
imports: import sys
label_desc: Use image node_id 1 to create a new Progbar object from inherited base classes: object with example: obj = Progbar(loader, metrics)