context[this.alias] = [];
var list = this.expression.resolve(context);
if(list){var last = null;
var stack = [];
for(var i = 0; i < list.length; i++){var id = list[i][this.key];
if(last !== id){this._push(context[this.alias], last, stack);
last = id;
stack = [list[i]];
}else{
stack.push(list[i]);
}}this._push(context[this.alias], last, stack);
}return buffer;