title: Elastic Search number of object passed must be even
body: <p>I am learning about elastic search and I am following <a href="https://www.adictosaltrabajo.com/tutoriales/primeros-pasos-elasticsearch/" rel="noreferrer">the next tutorial</a>, but I get the next error </p>
  
  <pre><code>Exception in thread "main" java.lang.IllegalArgumentException: The number of object passed must be even but was [1]
  at  org.elasticsearch.action.index.IndexRequest.source(IndexRequest.java:451)
  at elastic.elasti.App.lambda$0(App.java:55)
  at java.util.ArrayList.forEach(ArrayList.java:1249)
  at elastic.elasti.App.indexExampleData(App.java:53)
  at elastic.elasti.App.main(App.java:45)
  </code></pre>
  
  <p>Could you help me to fix it please?</p>
  
  <pre><code>public class App 
  {
      public static void main( String[] args ) throws TwitterException, UnknownHostException
      {
      System.out.println( "Hello World!" );
      List tweetJsonList = searchForTweets();
  
      Client client = TransportClient.builder().build()
              .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));
      String index = "tweets_juan";
      client.admin().indices()
                      .create(new CreateIndexRequest(index))
                      .actionGet();
      indexExampleData(client, tweetJsonList, index);
      searchExample(client);
  }
  public static void indexExampleData(Client client, List tweetJsonList, String index) {
  
  
      BulkRequestBuilder bulkRequestBuilder = client.prepareBulk();
  
      tweetJsonList.forEach((jsonTweet) -&gt; {
          bulkRequestBuilder.add(new IndexRequest(index, "tweets_juan")
                  .source(jsonTweet));
      });
  
      BulkResponse bulkItemResponses = bulkRequestBuilder.get();
  }
  
  
  
  
  public static void searchExample(Client client) {
      BoolQueryBuilder queryBuilder = QueryBuilders
              .boolQuery()
              .must(termsQuery("text", "españa"));
  
      SearchResponse searchResponse = client.prepareSearch("tweets_juan")
              .setQuery(queryBuilder)
              .setSize(25)
              .execute()
              .actionGet();
       }
  
  public static List searchForTweets() throws TwitterException {
      Twitter twitter = new TwitterFactory().getInstance();
      Query query = new Query("mundial baloncesto");
      List tweetList = new ArrayList&lt;&gt;();
      for (int i = 0; i &lt; 10; i++) {
          QueryResult queryResult = twitter.search(query);
          tweetList.addAll(queryResult.getTweets());
          if (!queryResult.hasNext()) {
              break;
          }
          query = queryResult.nextQuery();
      }
      Gson gson = new Gson();
  
      return (List) tweetList.stream().map(gson::toJson).collect(Collectors.toList());
      }
  }
  </code></pre>