A DistributionCut defines a TimeSeries and thresholds used for
measuring good service and total service. The TimeSeries must have
ValueType = DISTRIBUTION and MetricKind = DELTA or
MetricKind = CUMULATIVE. The computed good_service will be the
count of values x in the Distribution such that
range.min <= x < range.max.
Range of values considered "good." For a one-sided range, set
one bound to an infinite value.