docstr: Called when the prediction begins.
docstr_tok: ["Called","when","the","prediction","begins","."]
code: def on_prediction_start(self, **kwargs) -> None:
      """Called when the prediction begins."""
      for callback in self.callbacks:
          callback.on_prediction_start(**kwargs)
  
imports: from abc import ABC
  from typing import List
  from mmf.trainers.callbacks.base import Callback
label_desc: Use image node_id 18 for calling the TrainerCallbackHookMixin obj's underlying member method code with example usage: obj.on_prediction_start() without return types