Pick the (key, unit) pair to use for a PID under the active units
preference. When units === 'metric' and the catalog entry carries
an altUnit.metric companion, returns the metric key + unit; in
every other case returns the catalog entry's native key + unit, or
the raw input + an empty unit when the PID isn't in the catalog.
Charts and tables that want runtime unit swapping read their series
key + unit through this helper instead of hardcoding 'speed_mph' /
'mph' constants.
Pick the (key, unit) pair to use for a PID under the active units preference. When
units === 'metric'and the catalog entry carries analtUnit.metriccompanion, returns the metric key + unit; in every other case returns the catalog entry's native key + unit, or the raw input + an empty unit when the PID isn't in the catalog.Charts and tables that want runtime unit swapping read their series key + unit through this helper instead of hardcoding
'speed_mph'/'mph'constants.