presto-main/src/main/java/io/prestosql/execution/Lifespan.java/Lifespan/equals
class Lifespan:    @Override
    public boolean equals(Object o)
    {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        Lifespan that = (Lifespan) o;
        return grouped == that.grouped &&
                groupId == that.groupId;
    }