Add a TODO to use binary search in the range partitioner.
Add a TODO to use binary search in the range partitioner.

liyuqi/SparkR-pkg,xzw0005/SparkR-pkg,amplab-extras/SparkR-pkg,amplab-extras/SparkR-pkg,Liziyao/SparkR-pkg,rickyHong/sparkR-dist,xzw0005/SparkR-pkg,kimchitsigai/SparkR-pkg,RevolutionAnalytics/SparkR-pkg,nvoron23/SparkR-pkg,xzw0005/SparkR-pkg,RevolutionAnalytics/SparkR-pkg,amplab-extras/SparkR-pkg,LeoYao/SparkR-pkg,kcompher/SparkR-pkg,Liziyao/SparkR-pkg,liyuqi/SparkR-pkg,rickyHong/sparkR-dist,kimchitsigai/SparkR-pkg,nvoron23/SparkR-pkg,LeoYao/SparkR-pkg,kuch4r/SparkR-pkg,EugenePig/SparkR-pkg,liyuqi/SparkR-pkg,kcompher/SparkR-pkg,kcompher/SparkR-pkg,EugenePig/SparkR-pkg,rickyHong/sparkR-dist,rickyHong/sparkR-dist,kimchitsigai/SparkR-pkg,kuch4r/SparkR-pkg,RevolutionAnalytics/SparkR-pkg,xzw0005/SparkR-pkg,LeoYao/SparkR-pkg,RevolutionAnalytics/SparkR-pkg,kuch4r/SparkR-pkg,LeoYao/SparkR-pkg,kuch4r/SparkR-pkg,EugenePig/SparkR-pkg,liyuqi/SparkR-pkg,Liziyao/SparkR-pkg,Draki/SparkR-pkg,kcompher/SparkR-pkg,nvoron23/SparkR-pkg,Draki/SparkR-pkg,amplab-extras/SparkR-pkg,Draki/SparkR-pkg,Liziyao/SparkR-pkg,nvoron23/SparkR-pkg