Whether a given MetricDescriptorType value is a gauge.

    :type md_type: int
    :param md_type: A MetricDescriptorType enum value.

def is_gauge(md_type):
    """Whether a given MetricDescriptorType value is a gauge.

    :type md_type: int
    :param md_type: A MetricDescriptorType enum value.
    """
    if md_type not in metric_descriptor.MetricDescriptorType:
        raise ValueError  # pragma: NO COVER

    return md_type in {
        metric_descriptor.MetricDescriptorType.GAUGE_INT64,
        metric_descriptor.MetricDescriptorType.GAUGE_DOUBLE,
        metric_descriptor.MetricDescriptorType.GAUGE_DISTRIBUTION
    }