@Override
    public String toString() {
        StringBuilder buf = new StringBuilder();
        buf.append(this.getClass().getName()).append(": ");
        buf.append("outputFormat=").append(outputFormat).append(", ");
        if (count > 0 && outputFormat == AssumedType.GAUGE) {
            buf.append("max=").append(max).append(", ");
            buf.append("min=").append(min).append(", ");
            buf.append("sum=").append(sum).append(", ");
        }
        if (histogram != null) {
            buf.append("histogram=").append(histogram).append(", ");
        }
        if (metricSettings != null) {
            buf.append("metricSettings=").append(metricSettings).append(", ");
        }
        buf.append("current=").append(current).append(", ");
        buf.append("count=").append(count);
        return buf.toString();
    }
A gauge or a counter or... who knows? The class for storing a metric when the
metric has not been declared.

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