private PointBuilder set(String axisName, Value w) {
        // handle setting same axis multiple times nicely
        int i = Collections.binarySearch(dimensions, axisName);
        if (i < 0) {
            dimensions.add(~i, axisName);
            location.add(~i, w);
        } else {
            // only set location, dim obviously exists
            location.set(i, w);
        }
        return this;
    }
Set a named dimension to a string value.

@param dimensionName the name of the dimension to set
@param dimensionValue to value for the given dimension
@return this, to facilitate chaining
container-core/src/main/java/com/yahoo/metrics/simple/PointBuilder.java