title: @Relation Room DB with multiple columns
body: <p>If i want to related 2 tables and the relation is not only one column but more, is there a way to use the Room @Relation annotation with more arguments to achive that? Perhaps somehting like below</p>
  
  <pre><code>@Relation(parentColumn = "{message_id,account_id}", entityColumn = "{message_id, from_account_id}", entity = Message::class)
      var messageList: List&lt;Message&gt; = ArrayList()
  </code></pre>
  
  <p>So that the join has more than one constraint?</p>