if (doc.containsKey('end_time') && doc.containsKey('start_time') && !doc['end_time'].empty && !doc['start_time'].empty) { return (doc['end_time'].value.toInstant().toEpochMilli() - doc['start_time'].value.toInstant().toEpochMilli()) / 1000; } return null;
script for elastic duation