public String toXml(String tab) {StringBuilder builder = new StringBuilder();builder.append(tab).append("<").append(getRecordName()).append(">\n");for (EscherRecord escherRecord : getEscherRecords()) {builder.append(escherRecord.toXml(tab + "\t"));}builder.append(tab).append("</").append(getRecordName()).append(">\n");return builder.toString();}