title: NEST: How to query against multiple indices and handle different subclasses (document types)?
body: <p>I’m playing around with ElasticSearch in combination with NEST in my C# project. My use case includes several indices with different document types which I query separately so far. Now I wanna implement a global search function which queries against all existing indices, document types and score the result properly. </p>
  
  <p>So my question: How do I accomplish that by using NEST?</p>
  
  <p>Currently I’m using the function <code>SetDefaultIndex</code> but how can I define multiple indices?</p>
  
  <p>Maybe for a better understanding, this is the query I wanna realize with NEST:</p>
  
  <pre><code>{
    "query": {
      "indices": {
        "indices": [
          "INDEX_A",
          "INDEX_B"
        ],
        "query": {
          "term": {
            "FIELD": "VALUE"
          }
        },
        "no_match_query": {
          "term": {
            "FIELD": "VALUE"
          }
        }
      }
    }
  }
  </code></pre>
  
  <p>TIA</p>