class_docstr: Container holding a list of callbacks.
code: def on_train_begin(self, logs=None):
      self.has_val_data = logs["has_val_data"]
      logs = logs or {}
      self.start_time_s, self.start_time_date = _get_current_time()
      logs["start_time"] = self.start_time_date
      logs["start_time_s"] = self.start_time_s
      for callback in self.callbacks:
          callback.on_train_begin(logs)
  
file_path: pywick/pywick/callbacks/CallbackContainer.py
imports: import time
  import datetime
label_desc: Use image node_id 9 for calling the CallbackContainer obj's underlying member method code with example usage: obj.on_train_begin(logs) without return types