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

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