# Functions
MustRegister() registers the CapacityUsage metrics so they can be scraped by Prometheus, exiting on failure.
NewCapacityUsage() returns a CapacityUsage with a new set of labels to record the utilization of a limited resource where this utilization might spike for a short period and so a single Prometheus Gauge is not sufficient to capture such spikes.
Register() registers the CapacityUsage metrics so they can be scraped by Prometheus, returning an error on failure.
# Structs
A CapacityUsage uses two Prometheus gauge metrics, by default, "capacity_min_utilization" and "capacity_max_utilization".