title: How to query for a specific document by _id using the elasticsearch Nest client
body: <p>I have a specific document that I want to retrieve. The id value was assigned by elastic search and therefore does not appear in the <code>_source</code> section of the document.</p>
  <p>I believe there should be an <code>Ids</code> function but I can't find it in the NEST documentation.
  The following results in:
  <code>Cannot convert lambda expression to type 'Id' because it is not a delegate type</code></p>
  <pre><code>var queryResponse = 
    client.Search&lt;Dictionary&lt;string, object&gt;&gt;(
      s =&gt; s.Query(
        q =&gt; q.Ids( 
          i =&gt; i.Values(v =&gt; &quot;_id_assigned_by_elastic&quot;)
        )
      )
    ).Hits.FirstOrDefault();
  
  Dictionary&lt;string,object&gt; doc = h.Source;
  </code></pre>
  <p>The Rest API docs show this example:</p>
  <pre><code>{
    &quot;query&quot;: {
      &quot;ids&quot; : {
        &quot;values&quot; : [&quot;1&quot;, &quot;4&quot;, &quot;100&quot;]
      }
    }
  }
  </code></pre>
  <p>There is no corresponding example for C# and the NEST client</p>