in geronimo-metrics-common/src/main/java/org/apache/geronimo/microprofile/metrics/common/HistogramImpl.java [281:293]
public double getValue(final double quantile) {
if (!(quantile >= 0 || quantile <= 1)) {
throw new IllegalArgumentException("Quantile " + quantile + " is invalid");
}
if (values.length == 0) {
return 0;
}
if (values.length == 1) {
return values[0].value;
}
final int idx = (int) Math.floor((values.length - 1) * quantile);
return sorted()[idx].value;
}