presto-main/src/main/java/io/prestosql/sql/analyzer/FeaturesConfig.java/FeaturesConfig/setSpillerThreads
class FeaturesConfig:    @Config("spiller-threads")
    @LegacyConfig("experimental.spiller-threads")
    public FeaturesConfig setSpillerThreads(int spillerThreads)
    {
        this.spillerThreads = spillerThreads;
        return this;
    }