code: public OvhOperation serviceName_output_elasticsearch_alias_aliasId_index_POST(String serviceName, String aliasId, String indexId) throws IOException {
  		String qPath = "/dbaas/logs/{serviceName}/output/elasticsearch/alias/{aliasId}/index";
  		StringBuilder sb = path(qPath, serviceName, aliasId);
  		HashMap<String, Object>o = new HashMap<String, Object>();
  		addBody(o, "indexId", indexId);
  		String resp = exec(qPath, "POST", sb.toString(), o);
  		return convertTo(resp, OvhOperation.class);
  	}
docs: Attach a elasticsearch index to specified elasticsearch alias
  
  REST: POST /dbaas/logs/{serviceName}/output/elasticsearch/alias/{aliasId}/index
  @param serviceName [required] Service name
  @param aliasId [required] Alias ID
  @param indexId [required] Index ID