private static AsyncClusterConnection mockAndInjectError(AsyncClusterConnection conn) {
    AsyncClusterConnection errConn = spy(conn);
    doReturn(failedFuture(new IOException("injecting bulk load error"))).when(errConn).bulkLoad(
      any(), anyList(), any(), anyBoolean(), any(), any(), anyBoolean(), anyList(), anyBoolean());
    return errConn;
  }
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