Represent mean and sum as untyped values (#254)
Represent mean and sum as untyped values (#254)

Gauges are a special type of value and their value is
determined by running a function that calculates the
some value and reports on the gauge usually periodically.

Sum and mean are not gauges but untyped simple metrics.
census-instrumentation/opencensus-go,census-instrumentation/opencensus-go,census-instrumentation/opencensus-go