code: def test_init(self):
      model_selection = ModelSelection()
      self.assertIsNotNone(model_selection.metrics)
      self.assertIsNone(model_selection.last_model_id)
      self.assertEqual(4, len(model_selection.metrics))
  
imports: import unittest
  from small_text.training.metrics import Metric
  from small_text.training.model_selection import ModelSelectionResult, ModelSelection, NoopModelSelection
label_desc: Use image node_id 1 for calling the ModelSelectionTest obj's underlying member method code with example usage: obj.test_init() without return types