public static QuantileDigest merge(List<QuantileDigest> digests) {
if (digests.isEmpty()) {
throw new RuntimeException("Digests to be unioned should not be empty!");
}
QuantileDigest ret = digests.get(0);
for (int i = 1; i < digests.size(); i++) {
ret.merge(digests.get(i));
}
return ret;
}
public QuantileDigest(QuantileDigest quantileDigest) {
this(quantileDigest.getMaxError(), quantileDigest.getAlpha());
merge(quantileDigest);
}