code: def test_save(self, mock_save_check):
      state = {}
      check = MostRecent("test_file.pt")
  
      check.on_checkpoint(state)
      check.on_checkpoint(state)
  
      self.assertTrue(mock_save_check.call_count == 2)
  
imports: from unittest import TestCase
  from mock import patch, Mock
  import torchbearer
  from torchbearer import Trial
  from torchbearer.callbacks.checkpointers import _Checkpointer, ModelCheckpoint, MostRecent, Interval, Best
  import warnings
label_desc: Use image node_id 1 for calling the TestMostRecent obj's underlying member method code with example usage: obj.test_save(mock_save_check) without return types