index.field.click_count=click_count
index.field.config_id=config_id
index.field.expires=expires
index.field.url=url
index.field.doc_id=doc_id
index.field.id=_id
index.field.version=_version
index.field.seq_no=_seq_no
index.field.primary_term=_primary_term
index.field.lang=lang
index.field.has_cache=has_cache
index.field.last_modified=last_modified
index.field.anchor=anchor
index.field.segment=segment

    /** The key of the configuration. e.g. _version */
    String INDEX_FIELD_VERSION = "index.field.version";

    /** The key of the configuration. e.g. _seq_no */
    String INDEX_FIELD_seq_no = "index.field.seq_no";

    /** The key of the configuration. e.g. _primary_term */
    String INDEX_FIELD_primary_term = "index.field.primary_term";

    /** The key of the configuration. e.g. lang */

                    final Long seqNo = (Long) entity.remove(fessConfig.getIndexFieldSeqNo());
                    final Long primaryTerm = (Long) entity.remove(fessConfig.getIndexFieldPrimaryTerm());
                    if (seqNo != null && primaryTerm != null && oldId != null) {
                        searchEngineClient.delete(index, oldId, seqNo, primaryTerm);
                    }
                }

                    final Number seqNo = (Number) entity.remove(fessConfig.getIndexFieldSeqNo());
                    final Number primaryTerm = (Number) entity.remove(fessConfig.getIndexFieldPrimaryTerm());
                    if (seqNo != null && primaryTerm != null && oldId != null) {
                        searchEngineClient.delete(index, oldId, seqNo, primaryTerm);
                    }
                }

    }

    public boolean delete(final String index, final String id, final Number seqNo, final Number primaryTerm) {
        try {
            final DeleteRequestBuilder builder = client.prepareDelete().setIndex(index).setId(id).setRefreshPolicy(RefreshPolicy.IMMEDIATE);
            if (seqNo != null) {
                builder.setIfSeqNo(seqNo.longValue());
            }
            if (primaryTerm != null) {