Represents a histogram metric used for collecting and recording data
distributions. The Histogram struct contains labels that categorize the
histogram and a channel for sending HistogramMessage instances to record
the data.
A guard used for timing the duration of an operation and recording it in a
Histogram. The HistogramTimerGuard starts a timer upon creation and,
when dropped, records the elapsed time into the associated Histogram.
Represents a collection of histograms for managing multiple labeled metrics.
The HistogramVec struct allows for sending HistogramMessage instances
via a channel to record data in a particular histogram, providing a way to
track different metrics concurrently.