title: GraphQL Federation: Is it possible to have multiple service contribute to a list/array result?
body: <p>Assuming I have the following GraphQL schema defined:</p>
  <pre><code>type Widgets {
    id: ID!
    name: String!
  }
  
  type Basket {
    id: ID!
    widgets: [Widgets]!
  }
  </code></pre>
  <p>And that I have a widget service that provides those results.</p>
  <p>But now I have a new service &quot;NEW widget&quot; service, that I'd like to contribute to the list of widgets. So the widget service provides a list of widgets, but the &quot;NEW widget&quot; service has a few more widgets to add to the list.</p>
  <p><strong>Is this possible?</strong></p>
  <p>I know I could add a new field to the Widget or Basket types from &quot;NEW widget&quot; service, but I'm wondering if I can contribute results to a list from another service.</p>
  <p>This that possible from the GraphQL spec or Apollo federation?</p>