    def validate_metrics(self, metric_name, help_text, increments):
        """
        WSGI app serves the metrics from the provided registry.
        """
        self.increment_metrics(metric_name, help_text, increments)
        # Create and run WSGI app
        app = make_wsgi_app(self.registry)
        outputs = app(self.environ, self.capture)
        # Assert outputs
        self.assert_outputs(outputs, metric_name, help_text, increments, compressed=False)
WSGI app serves the metrics from the provided registry.
tests/test_wsgi.py