docs: public void createIndex(String index, boolean ignoreErrors, String indexSettings) throws IOException {
          logger.debug("create index [{}]", index);
          logger.trace("index settings: [{}]", indexSettings);
  
          try {
              Response response = lowLevelClient.performRequest("PUT", "/" + index,
                      Collections.emptyMap(), createEntity(indexSettings));
              logger.trace("create index response: {}", asMap(response));
          } catch (ResponseException e) {
              if (e.getResponse().getStatusLine().getStatusCode() == 400 &&
                      (e.getMessage().contains("index_already_exists_exception"))) {
                  if (!ignoreErrors) {
                      throw new RuntimeException("index already exists");
                  }
                  logger.trace("index already exists. Ignoring error...");
                  return;
              }
              throw e;
          }
          waitForHealthyIndex(index);
      }