private static <T> CompletableFuture<T> failedFuture(Throwable error) {
    CompletableFuture<T> future = new CompletableFuture<>();
    future.completeExceptionally(error);
    return future;
  }
Checks that all columns have the expected value and that there is the expected number of rows.
hbase-server/src/test/java/org/apache/hadoop/hbase/tool/TestBulkLoadHFilesSplitRecovery.java