docs: public JestClient createLocalClient(String className, String fieldName, String indexName, String defaultIndexName) {
          String clientKey = "local:" + className + '/' + fieldName; //$NON-NLS-1$
          synchronized (clients) {
              if (clients.containsKey(clientKey)) {
                  return clients.get(clientKey);
              } else {
                  try {
                      Class<?> clientLocClass = Class.forName(className);
                      Field field = clientLocClass.getField(fieldName);
                      JestClient client = (JestClient) field.get(null);
                      clients.put(clientKey, client);
                      initializeClient(client, indexName, defaultIndexName);
                      return client;
                  } catch (ClassNotFoundException | NoSuchFieldException | SecurityException
                          | IllegalArgumentException | IllegalAccessException e) {
                      throw new RuntimeException("Error using local elasticsearch client.", e); //$NON-NLS-1$
                  }
              }
          }
      }