Perhaps we could put a comment on this block. I believe the intention is to explicitly affirm breaking API changes _to_ the given SPARK_VERSION (rather than _from_ it). That is, we should ignore any errors about util.XORShiftRandom from versions prior to Spark 1.0 when being compared to Spark 1.0, but we wouldn't ignore errors related to util.XORShiftRandom if we were comparing Spark 1.0 to future versions. Is my understanding correct?