//MAP FUNCTION
function () {
              emit({style: this.style}, {ids : [this._id], count: 1});
           }

//REDUCE FUNCTION
function (key, values) {
				var res = {ids: [], count: 0};
 				values.forEach(function(value){
    				      res.ids = value.ids.concat(res.ids);
    				      res.count += value.count;
 				});

  				return res;
}


//FINALIZE FUNCTION
function (key, res) {
			 if (res.count > 1) { return res; } else { return null; }
  			}