{
        might_have: {
            fetch: 0
        },
        has_many: {
            fetch: 0
        },
        sets: [{
            class: 'CD',
            ids: ['5']
        }, {
            class: 'Artist',
            ids: ['1'],
            fetch: [{
                rel: cds,
                quantity: all
            }]
        }],
        rules: {
            'CD': {
                cond: [{ 'tags.tag': 'Cheesy' }],
                join: ['tags'],
                fetch: [{
                    rel: tracks,
                    cond: { position: 2 }
                }]
            }                    
        }
}