spark git commit: [SPARK-15875] Try to use Seq.isEmpty and Seq.nonEmpty instead of Seq.length == 0 and Seq.length > 0

Repository: spark Updated Branches: refs/heads/branch-2.0 96bb1476c -> 8b6742a37 [SPARK-15875] Try to use Seq.isEmpty and Seq.nonEmpty instead of Seq.length == 0 and Seq.length > 0 ## What changes were proposed in this pull request? In scala, immutable.List.length is an expensive operation

spark git commit: [SPARK-15875] Try to use Seq.isEmpty and Seq.nonEmpty instead of Seq.length == 0 and Seq.length > 0

Repository: spark Updated Branches: refs/heads/master 865ec32dd -> 026eb9064 [SPARK-15875] Try to use Seq.isEmpty and Seq.nonEmpty instead of Seq.length == 0 and Seq.length > 0 ## What changes were proposed in this pull request? In scala, immutable.List.length is an expensive operation so