code: public JestClient createClient(Map<String, String> config, String defaultIndexName) {
          JestClient client;
          String indexName = config.get("client.index"); //$NON-NLS-1$
          if (indexName == null) {
              indexName = defaultIndexName;
          }
          client = createLocalClient(config, indexName, defaultIndexName);
          return client;
      }
docs: Creates a client from information in the config map.
  @param config the configuration
  @param defaultIndexName the default index to use if not specified in the config
  @return the ES client