export default new GraphQLObjectType(BookshelfType({
  name: 'Classroom',
  description: 'Need I say more?',
  // ...and an object gets passed into the fields to help with your model.
  fields: (model) => ({

    id: model.attr({
      type: new GraphQLNonNull(GraphQLInt),
      description: 'The id of the classroom.',
      // ...and you don't need to resolve table attributes.
    }),

    subject: model.belongsTo({
      type: SubjectType, // And use the right association type...
      description: 'The subject of the classroom.',
      // And you get one-to-one relationships for free
    }),

    students: model.hasMany({
      type: new GraphQLList(StudentType), // And make sure you use `GraphQLList`
      description: 'Students in the classroom.',
      // Now you have associated collections for free
    }),

    homeworks: model.hasMany({
      type: new GraphQLList(HomeworkType),
      description: 'Homework submitted to the classroom (latest to oldest).',
      // Define a resolve function...
      resolve: (qb) => {
        // And get a sweet KnexJS query builder
        qb.orderBy('created_at', 'DESC');
      }
    }),

    size: {
      type: GraphQLInt,
      description: 'How many students there are in the class.',
      resolve: (model) => {
        // And do it the old fashioned way
        return model.studentCount();
      },
    }
  }),
}));