title: Include NULL values in Range Query Elasticsearch
body: <p>I have framed Range query as below - Java High Level REST Client</p>
  
  <pre><code>QueryBuilder rangeQu = QueryBuilders.rangeQuery("price").gt(30).lt(5000);
  </code></pre>
  
  <p>In this I want to include NULL/Empty values as well. How to include it?</p>