return "id";
                case FessConfig.INDEX_FIELD_VERSION:
                    return "_version";
                case FessConfig.INDEX_FIELD_seq_no:
                    return "_seq_no";
                case FessConfig.INDEX_FIELD_primary_term:
                    return "_primary_term";
                case FessConfig.INDEX_FIELD_LANG:
                    return "lang";

        }

        @Override
        public String getIndexFieldVersion() {
            return "_version";
        }

        @Override
        public String getIndexFieldSeqNo() {
            return "_seq_no";
        }

        @Override
        public String getIndexFieldPrimaryTerm() {
            return "_primary_term";
        }

        @Override

index.field.doc_id=doc_id
# Field name for internal ID in the index.
index.field.id=_id
# Field name for version in the index.
index.field.version=_version
# Field name for sequence number in the index.
index.field.seq_no=_seq_no
# Field name for primary term in the index.
index.field.primary_term=_primary_term
# Field name for language in the index.
index.field.lang=lang
# Field name for cache status in the index.

    /** 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 */

        if (indexOption != null) {
            indexOption.callback(builder);
        }
        final Long seqNo = esEntity.asDocMeta().seqNo();
        if (seqNo != null && seqNo.longValue() != SequenceNumbers.UNASSIGNED_SEQ_NO) {
            esEntity.asDocMeta().seqNo(seqNo);
        }
        final Long primaryTerm = esEntity.asDocMeta().primaryTerm();

        }

        public Long version() {
            return version;
        }

        public DocMeta seqNo(Long seqNo) {
            this.seqNo = seqNo;
            return this;
        }

        public Long seqNo() {
            return seqNo;
        }

        public DocMeta primaryTerm(Long primaryTerm) {
            this.primaryTerm = primaryTerm;
            return this;

            @Override
            public String getIndexFieldRole() {
                return "role";
            }

            @Override
            public String getIndexFieldSeqNo() {
                return "seq_no";
            }

            @Override
            public String getIndexFieldVersion() {
                return "version";
            }

            @Override

        if (indexOption != null) {
            indexOption.callback(builder);
        }
        final Long seqNo = esEntity.asDocMeta().seqNo();
        if (seqNo != null && seqNo.longValue() != SequenceNumbers.UNASSIGNED_SEQ_NO) {
            esEntity.asDocMeta().seqNo(seqNo);
        }
        final Long primaryTerm = esEntity.asDocMeta().primaryTerm();

        }

        public Long version() {
            return version;
        }

        public DocMeta seqNo(Long seqNo) {
            this.seqNo = seqNo;
            return this;
        }

        public Long seqNo() {
            return seqNo;
        }

        public DocMeta primaryTerm(Long primaryTerm) {
            this.primaryTerm = primaryTerm;
            return this;

        }

        public Long version() {
            return version;
        }

        public DocMeta seqNo(Long seqNo) {
            this.seqNo = seqNo;
            return this;
        }

        public Long seqNo() {
            return seqNo;
        }

        public DocMeta primaryTerm(Long primaryTerm) {
            this.primaryTerm = primaryTerm;
            return this;