public org.apache.flink.table.descriptors.Elasticsearch failureHandlerCustom(Class<? extends ActionRequestFailureHandler> failureHandlerClass) {
		internalProperties.putString(CONNECTOR_FAILURE_HANDLER, ElasticsearchValidator.CONNECTOR_FAILURE_HANDLER_VALUE_CUSTOM);
		internalProperties.putClass(CONNECTOR_FAILURE_HANDLER_CLASS, failureHandlerClass);
		return this;
	}
Configures a failure handling strategy in case a request to Elasticsearch fails.

<p>This strategy allows for custom failure handling using a {@link ActionRequestFailureHandler}.
elasticsearch5-xh/elasticsearch5-xh-sink/src/main/java/org/apache/flink/table/descriptors/Elasticsearch.java