code: def test_get_last_value():
      tracker = metrics_tracking.MetricsTracker()
      tracker.register("new_metric", "min")
      assert tracker.get_last_value("new_metric") is None
      tracker.set_history(
          "new_metric",
          [
              metrics_tracking.MetricObservation(1.0, 0),
              metrics_tracking.MetricObservation(2.0, 1),
              metrics_tracking.MetricObservation(3.0, 2),
          ],
      )
      assert tracker.get_last_value("new_metric") == 3.0
  
imports: import random
  import numpy
  import pytest
  from keras_tuner.backend.keras import losses
  from keras_tuner.backend.keras import metrics
  from keras_tuner.engine import metrics_tracking
label_desc: Use image node_id 11 for calling a global function with example usage: test_get_last_value() without return types