def METHOD_NAME(self):
    """Test that we can track histogram in Service303"""
    # Add a histogram with a label to the regisry
    process_max_metric_name = 'process_max_fds'
    c = Histogram(
        process_max_metric_name, 'A summary', ['result'],
        registry=self.registry, buckets=[0, 2, float('inf')],
    )
    c.labels('success').observe(1.23)
    c.labels('failure').observe(2.34)
    # Build proto outputs
    histogram1 = metrics_pb2.Histogram(sample_count=1, sample_sum=1.23)
    histogram1.bucket.add(upper_bound=0, cumulative_count=0)
    histogram1.bucket.add(upper_bound=2, cumulative_count=1)
    histogram1.bucket.add(upper_bound=float('inf'), cumulative_count=1)
    histogram2 = metrics_pb2.Histogram(sample_count=1, sample_sum=2.34)
    histogram2.bucket.add(upper_bound=0, cumulative_count=0)
    histogram2.bucket.add(upper_bound=2, cumulative_count=0)
    histogram2.bucket.add(upper_bound=float('inf'), cumulative_count=1)
    metric1 = metrics_pb2.Metric(
        histogram=histogram1,
        timestamp_ms=1234000,
    )
    metric2 = metrics_pb2.Metric(
        histogram=histogram2,
        timestamp_ms=1234000,
    )
    family = metrics_pb2.MetricFamily(
        name=process_max_metric_name,
        type=metrics_pb2.HISTOGRAM,
    )
    metric1.label.add(
        name='result',
        value='success',
    )
    metric2.label.add(
        name='result',
        value='failure',
    )
    family.metric.extend([metric1, metric2])
    with unittest.mock.patch('time.time') as mock_time:
        mock_time.side_effect = lambda: 1234
        self.assertCountEqual(
            list(metrics_export.get_metrics(self.registry))[0].metric,
            family.metric,
        )