old_contents: import OsfSerializer from './osf-serializer';
  
  export default OsfSerializer.extend({
      serialize: function(snapshot, options) {
          // Restore relationships to serialized data
          var serialized = this._super(snapshot, options);
          // APIv2 expects contributor information to be nested under relationships.
          serialized.data.relationships = {
              users: {
                  data: {
                      id: snapshot.record.get('userId') || snapshot.record.id.split('-')[1],
                      type: 'users'
                  }
              }
          };
          return serialized;
      },
  });
  
new_contents: import OsfSerializer from './osf-serializer';
  
  export default OsfSerializer.extend({
      serialize: function(snapshot, options) {
          // Restore relationships to serialized data
          var serialized = this._super(snapshot, options);
          // APIv2 expects contributor information to be nested under relationships.
          serialized.data.relationships = {
              users: {
                  data: {
  		    // TODO changeme when https://github.com/CenterForOpenScience/osf.io/pull/5824 goes in
                      id: snapshot.record.get('id') || snapshot.record.get('userId') || snapshot.record.id.split('-')[1],
                      type: 'users'
                  }
              }
          };
          return serialized;
      }
  });
  
subject: Use Contrib.id until compound ids are ready