class_docstr: Container abstracting a list of callbacks.
class_docstr_tok: ["Container","abstracting","a","list","of","callbacks","."]
docstr: Adds `Callback`s that are always present.
docstr_tok: ["Adds","`","Callback","`","s","that","are","always","present","."]
code: def _add_default_callbacks(self, add_history, add_progbar):
      """Adds `Callback`s that are always present."""
      self._progbar = None
      self._history = None
  
      for cb in self.callbacks:
          if isinstance(cb, ProgbarLogger):
              self._progbar = cb
          elif isinstance(cb, History):
              self._history = cb
  
      if self._history is None and add_history:
          self._history = History()
          self.callbacks.append(self._history)
  
      if self._progbar is None and add_progbar:
          self._progbar = ProgbarLogger()
          self.callbacks.append(self._progbar)
  
imports: import tree
  from keras.api_export import keras_export
  from keras.callbacks.callback import Callback
  from keras.callbacks.history import History
  from keras.callbacks.progbar_logger import ProgbarLogger
label_desc: Use image node_id 2 for calling the CallbackList obj's underlying member method code with example usage: obj._add_default_callbacks(add_history, add_progbar) without return types