code: public boolean isExists(String index) {
          IndicesExistsRequestBuilder indicesExistsRequestBuilder =
                  admin().indices().prepareExists(index);
          return JMElasticsearchUtil
                  .logRequestQueryAndReturn("isExists",
                          indicesExistsRequestBuilder,
                          indicesExistsRequestBuilder.execute())
                  .isExists();
      }
docs: Is exists boolean.
  
  @param index the index
  @return the boolean