class_docstr: Error: model not found
code: def __str__(self):
      msg = "Model {} Not Found.\nAvailiable models:\n".format(
          self.model_name
      )
      for model in self.avail_models:
          msg += "  {}\n".format(model)
      return msg
  
imports: import os
  import logging
  import paddle.fluid
label_desc: Use image node_id 2 for calling the ModelNotFoundError obj's underlying member method code with example usage: obj.__str__() and returns: msg