diff --git a/src/core/structure/tree.js b/src/core/structure/tree.js
index 32e7665b4..359af5cab 100644
--- a/src/core/structure/tree.js
+++ b/src/core/structure/tree.js
@@ -30,20 +30,23 @@
         initTree: function (nodes) {
             var self = this;
             this.clear();
-            var queue = [];
+            var queue = new Set();
+
             BI.each(nodes, function (i, node) {
                 var n = new BI.Node(node);
                 n.set("data", node);
                 self.addNode(n);
-                queue.push(n);
+                queue.add(n);
             });
-            while (!BI.isEmpty(queue)) {
-                var parent = queue.shift();
+            while (queue.size > 0) {
+                var [parent] = queue;
+                queue.delete(parent);
+
                 var node = parent.get("data");
                 BI.each(node.children, function (i, child) {
                     var n = new BI.Node(child);
                     n.set("data", child);
-                    queue.push(n);
+                    queue.add(n);
                     self.addNode(parent, n);
                 });
             }