presto-client/src/main/java/io/prestosql/client/StatementStats.java/StatementStats/getProgressPercentage
class StatementStats:    @JsonProperty
    public OptionalDouble getProgressPercentage()
    {
        if (!scheduled || totalSplits == 0) {
            return OptionalDouble.empty();
        }
        return OptionalDouble.of(min(100, (completedSplits * 100.0) / totalSplits));
    }