class_docstr: LambdaCallback. Just a shorthand for creating a callback class.
  
  See :class:`matchzoo.tuner.callbacks.Callback` for more details.
  
  Example:
  
      >>> import matchzoo as mz
      >>> model = mz.models.Naive()
      >>> model.guess_and_fill_missing_params(verbose=0)
      >>> data = mz.datasets.toy.load_data()
      >>> data = model.get_default_preprocessor().fit_transform(
      ...     data, verbose=0)
      >>> def show_inputs(*args):
      ...     print(' '.join(map(str, map(type, args))))
      >>> callback = mz.auto.tuner.callbacks.LambdaCallback(
      ...     on_run_start=show_inputs,
      ...     on_build_end=show_inputs,
      ...     on_run_end=show_inputs
      ... )
      >>> _ = mz.auto.tune(
      ...     params=model.params,
      ...     train_data=data,
      ...     test_data=data,
      ...     num_runs=1,
      ...     callbacks=[callback],
      ...     verbose=0,
      ... ) # noqa: E501
      <class 'matchzoo.auto.tuner.tuner.Tuner'> <class 'dict'>
      <class 'matchzoo.auto.tuner.tuner.Tuner'> <class 'matchzoo.models.naive.Naive'>
      <class 'matchzoo.auto.tuner.tuner.Tuner'> <class 'matchzoo.models.naive.Naive'> <class 'dict'>
docstr: Init.
docstr_tok: ["Init","."]
code: def __init__(
      self, on_run_start=None, on_build_end=None, on_run_end=None
  ):
      """Init."""
      self._on_run_start = on_run_start
      self._on_build_end = on_build_end
      self._on_run_end = on_run_end
  
imports: from matchzoo.engine.base_model import BaseModel
  from matchzoo.auto.tuner.callbacks.callback import Callback
label_desc: Use image node_id 1 to create a new LambdaCallback object from inherited base classes: Callback with example: obj = LambdaCallback(on_run_start, on_build_end, on_run_end)