Meteor publish-with-relations complex use

publish.js

Meteor.publish('bike', function(id) {
  return Meteor.publishWithRelations({
    handle: this,
    collection: Bikes,
    filter: id,
    mappings: [
      {
        key: 'userId',
        options: { fields: config.users.publicFields },
        collection: Meteor.users
      }, {
        reverse: true,
        key: 'bikeId',
        collection: Pictures
      }, {
        reverse: true,
        key: 'bikeId',
        collection: Comments,
        options: {
          sort: { createdAt: -1 }
        },
        mappings: [
          {
            key: 'userId',
            collection: Meteor.users,
            options: { fields: config.users.publicFields }
          }
        ]
      }, {
        reverse: true,
        key: 'bikeId',
        collection: BikeParts,
        mappings: [
          {
            key: 'partId',
            collection: Parts,
            mappings: [
              { key: 'typeId', collection: PartTypes },
              { key: 'vendorId', collection: PartVendors }
            ]
          }, {
            key: 'userId',
            collection: Meteor.users,
            options: { fields: config.users.publicFields }
          }
        ]
      }
    ]
  });
});