code: def get_instance(page_to_consume):
      
      global _instances
      if isinstance(page_to_consume, basestring):
          uri = page_to_consume
          page_to_consume = consumepage.get_instance(uri)
      elif isinstance(page_to_consume, consumepage.ConsumePage):
          uri = page_to_consume.uri
      else:
          raise TypeError(
              "get_instance() expects a parker.ConsumePage "
              "or basestring derivative."
          )
  
      try:
          instance = _instances[uri]
      except KeyError:
          instance = ConsumeModel(page_to_consume)
          _instances[uri] = instance
  
      return instance
docs: Return an instance of ConsumeModel.