private static List<byte[]> createBoundaries(int stripeCount) {
    byte[][] keys = new byte[][] { KEY_A, KEY_B, KEY_C, KEY_D, KEY_E };
    assert stripeCount <= keys.length + 1;
    List<byte[]> boundaries = new ArrayList<>();
    boundaries.addAll(Arrays.asList(keys).subList(0, stripeCount - 1));
    return boundaries;
  }
@param l0Count Number of L0 files.
@param l0Size  Size of each file.
@param sizes   Sizes of the files; each sub-array representing a stripe.
@return Mock stripes.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/compactions/TestStripeCompactionPolicy.java