public org.apache.flink.table.descriptors.Elasticsearch index(String index) {
		internalProperties.putString(CONNECTOR_INDEX, index);
		return this;
	}
Declares the Elasticsearch index for every record. Required.

@param index Elasticsearch index
elasticsearch5-xh/elasticsearch5-xh-sink/src/main/java/org/apache/flink/table/descriptors/Elasticsearch.java