Elastic Search number of object passed must be even : <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>
