class_docstr: Attributes:
      params (dict): Contains ``'epoch'`` and ``'steps_per_epoch'`` keys which are passed to the
          when training. Contains ``'steps'`` when evaluating. May contain other keys.
      model (Model): A reference to the :class:`~poutyne.Model` object which is using the callback.
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docstr: Is called before the beginning of the testing.
  
  Args:
      logs (dict): Usually an empty dict.
docstr_tok: ["Is","called","before","the","beginning","of","the","testing",".","Args",":","logs","(","dict",")",":","Usually","an","empty","dict","."]
code: def on_test_begin(self, logs: Dict):
      """
      Is called before the beginning of the testing.
  
      Args:
          logs (dict): Usually an empty dict.
      """
      pass
  
imports: from typing import Dict, Sequence
label_desc: Use image node_id 18 for calling the Callback obj's underlying member method code with example usage: obj.on_test_begin(logs) without return types