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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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
    }