code: def test_model_deleted_case_epoch(self):
      temp_dir = self.get_temp_dir()
      backup_dir = file_utils.join(temp_dir, "subdir")
      self.assertFalse(file_utils.exists(backup_dir))
  
      model = self.make_model()
      cbk = callbacks.BackupAndRestore(backup_dir, save_freq="epoch")
  
      x_train = np.random.random((10, 3))
      y_train = np.random.random((10, 1))
      model.fit(
          x_train,
          y_train,
          batch_size=4,
          callbacks=[cbk],
          epochs=2,
          verbose=0,
      )
      self.assertFalse(file_utils.exists(backup_dir))
  
imports: import numpy
  import pytest
  from keras import callbacks
  from keras import layers
  from keras import testing
  from keras.models import Sequential
  from keras.utils import file_utils
label_desc: Use image node_id 5 for calling the BackupAndRestoreCallbackTest obj's underlying member method code with example usage: obj.test_model_deleted_case_epoch() without return types