+ prev: function() {
+ var myIdx = this.getIndex();
+ return myIdx > 0 ? this.parent().contents()[myIdx-1] : null;
+ },
+
+ next: function() {
+ if(this.isRoot()) {
+ return null;
+ }
+ var myIdx = this.getIndex(),
+ parentContents = this.parent().contents();
+ return myIdx < parentContents.length - 1 ? parentContents[myIdx+1] : null;
+ },
+