def METHOD_NAME(self):
    run = Run(system_tracking_interval=None)
    empty_context_idx = Context({}).idx
    for index in range(10):
        run.track({'numbers': index, 'squares': index**2})
    metric_infos = run.meta_run_tree.subtree(('traces', empty_context_idx))
    self.assertEqual('int', metric_infos['numbers', 'dtype'])
    self.assertEqual('int', metric_infos['squares', 'dtype'])
    self.assertEqual(9, metric_infos['numbers', 'last'])
    self.assertEqual(81, metric_infos['squares', 'last'])