public static Iterable<byte[]> iterateOnSplits(final byte[] a, final byte[] b, final int num) {
    return iterateOnSplits(a, b, false, num);
  }
Iterate over keys within the passed range, splitting at an [a,b) boundary.
hbase-common/src/main/java/org/apache/hadoop/hbase/util/Bytes.java