title: How to return an array in Protobuf service rpc
body: <p>I have the following schema in my <code>.proto</code> file:</p>
  
  <pre><code>service MyService {
      rpc GetItem (ItemQuery) returns (Item) {
      }
  }
  
  message ItemQuery {
      int id = 1;
  }
  message Item {
      int id = 1;
      string name = 2;
  }
  </code></pre>
  
  <p>Now I want to add another rpc method to return multiple Items.
  Something like this: </p>
  
  <pre><code>rpc GetItems (ItemsQuery) returns (repeated Item) {
  }
  </code></pre>
  
  <p>Is there a better way to do it than define an Items message?</p>