title: apollo (graphQL) - how to send array of object in queries
body: <p>I would like to send an array of object in a graphQL queries. But I don't have any idea how to type the pointer in the query $gallery:  where Type will be a simple datastructure like a class or dictionnary.</p>
  
  <pre><code> apollo_client.mutate({mutation: gql`
            mutation m(
              $title: String!, $gallery:&lt;Type?&gt;){
                mutatePmaGallery(pmaData:
                  {title: $title, gallery: $gallery}) {
                    pma{
                      id
                    }
                  }
                }`,
              variables: {
                title:      _this.state.title,
                gallery:    {&lt;Type?&gt;}
              })
  </code></pre>