private static boolean checkAclTag(byte[] acl, ExtendedCell cell) {
    Iterator<Tag> iter = PrivateCellUtil.tagsIterator(cell);
    while (iter.hasNext()) {
      Tag tag = iter.next();
      if (tag.getType() == TagType.ACL_TAG_TYPE) {
        Tag temp =
          TagBuilderFactory.create().setTagType(TagType.ACL_TAG_TYPE).setTagValue(acl).build();
        return Tag.matchingValue(tag, temp);
      }
    }
    return false;
  }
Test coprocessor methods
{@link RegionObserver#postIncrementBeforeWAL(ObserverContext, Mutation, List)} and
{@link RegionObserver#postAppendBeforeWAL(ObserverContext, Mutation, List)}. These methods may
change the cells which will be applied to memstore and WAL. So add unit test for the case which
change the cell's column family and tags.
hbase-server/src/test/java/org/apache/hadoop/hbase/coprocessor/TestPostIncrementAndAppendBeforeWAL.java