def assertMetricCompare(self, frozen_registry, predicate,<EOL>metric_name, registry=REGISTRY, **labels):
saved_value = self.getMetricFromFrozenRegistry(<EOL>metric_name, frozen_registry, **labels)<EOL>current_value = self.getMetric(metric_name, registry=registry,<EOL>**labels)<EOL>self.assertFalse(<EOL>current_value is None,<EOL>METRIC_DIFF_ERR_NONE_EXPLANATION % (<EOL>metric_name, self.formatLabels(labels),<EOL>saved_value,<EOL>current_value))<EOL>self.assertTrue(<EOL>predicate(saved_value, current_value),<EOL>METRIC_COMPARE_ERR_EXPLANATION % (<EOL>metric_name, self.formatLabels(labels),<EOL>saved_value,<EOL>current_value))<EOL>
Asserts that metric_name{**labels} changed according to a provided
        predicate function between the frozen registry and now. A
        frozen registry can be obtained by calling saveRegistry,
        typically at the beginning of a test case.