presto-main/src/main/java/io/prestosql/operator/aggregation/MergeQuantileDigestFunction.java/MergeQuantileDigestFunction/MergeQuantileDigestFunction
class MergeQuantileDigestFunction:    public MergeQuantileDigestFunction()
    {
        super(
                new FunctionMetadata(
                        new Signature(
                                NAME,
                                ImmutableList.of(comparableTypeParameter("T")),
                                ImmutableList.of(),
                                parametricType("qdigest", new TypeSignature("T")),
                                ImmutableList.of(parametricType("qdigest", new TypeSignature("T"))),
                                false),
                        true,
                        ImmutableList.of(new FunctionArgumentDefinition(false)),
                        false,
                        true,
                        "Merges the input quantile digests into a single quantile digest",
                        AGGREGATE),
                true,
                true);
    }