code: def test_check_point(self) -> None:
      from sklearn.datasets import load_breast_cancer
  
      X, y = load_breast_cancer(return_X_y=True)
      m = xgb.DMatrix(X, y)
      with tempfile.TemporaryDirectory() as tmpdir:
          check_point = xgb.callback.TrainingCheckPoint(
              directory=tmpdir, interval=1, name="model"
          )
          xgb.train(
              {"objective": "binary:logistic"},
              m,
              num_boost_round=10,
              verbose_eval=False,
              callbacks=[check_point],
          )
          for i in range(1, 10):
              assert os.path.exists(
                  os.path.join(
                      tmpdir,
                      f"model_{i}.{xgb.callback.TrainingCheckPoint.default_format}",
                  )
              )
  
          check_point = xgb.callback.TrainingCheckPoint(
              directory=tmpdir, interval=1, as_pickle=True, name="model"
          )
          xgb.train(
              {"objective": "binary:logistic"},
              m,
              num_boost_round=10,
              verbose_eval=False,
              callbacks=[check_point],
          )
          for i in range(1, 10):
              assert os.path.exists(
                  os.path.join(tmpdir, "model_" + str(i) + ".pkl")
              )
  
imports: import json
  import os
  import tempfile
  from typing import Union
  import pytest
  import xgboost
  from xgboost import testing
label_desc: Use image node_id 15 for calling the TestCallbacks obj's underlying member method code with example usage: obj.test_check_point() without return types