public Point getLocation() {
        return location;
    }
The name of the metric and its n-dimensional position. Basically a pair of a
Point and a metric name. Written to be robust against null input as the API
gives very little guidance, converting null to empty string/point.  Immutable.

@author Steinar Knutsen
container-core/src/main/java/com/yahoo/metrics/simple/Identifier.java