c.find({a: {$gt: 10}}, {sort: {b: -1, a: 1}, skip: 3, limit: 5}).fetch(), [
      {a: 14, b: 1, _id: '14_1'},
      {a: 15, b: 1, _id: '15_1'},
      {a: 16, b: 1, _id: '16_1'},
      {a: 17, b: 1, _id: '17_1'},