title: Custom query parser in search Api
body: <p>I have a custom query parser and I can query my Index using Sense as follows: </p>
  
  <pre><code>GET myIndex/_search
  {
    "query": {
      "myParser":{
        "query" : "blabla"
      } 
    }
  }
  </code></pre>
  
  <p>My question is, how can I parse the query with myParser in Search Api? How do I mention Parser in QueryBuilders?</p>