 = this.collection;
splices.forEach(function(s) {
var args = [ s.index, s.removed.length ].concat(s.added);
keys.splice.apply(keys, args);
for (var i = 0; i < s.added.length; i++) {
var item = c.getItem(s.added[i]);
var row = this._insertRow(s.index + i, pool, item);
this.rows.splice(s.index + i, 0, row);
}
}, this);
},
_detachRow: function(idx) {
var row = this.rows[idx];
var parentNode = Polymer.dom(this).parentNode;
for (var i = 0; i < row._children.length; i++) {
var el = row._children[i];
Polymer.dom(r