More efficient iteration.

src/standard/configure.html

@@ -46,13 +46,15 @@
     // storage for configuration
     _setupConfigure: function(initialConfig) {
       this._config = {};
-      // don't accept undefined values in intialConfig
-      for (var i in initialConfig) {
-        if (initialConfig[i] !== undefined) {
-          this._config[i] = initialConfig[i];
+      this._handlers = [];
+      if (initialConfig) {
+        // don't accept undefined values in intialConfig
+        for (var i in initialConfig) {
+          if (initialConfig[i] !== undefined) {
+            this._config[i] = initialConfig[i];
+          }
         }
       }
-      this._handlers = [];
     },
 
     // static attributes are deserialized into _config
@@ -87,9 +89,9 @@
       // get individual default values from property configs
       var config = {};
       // mixed-in behaviors
-      this.behaviors.forEach(function(b) {
-        this._configureProperties(b.properties, config);
-      }, this);
+      for (var i=0; i < this.behaviors.length; i++) {
+        this._configureProperties(this.behaviors[i].properties, config);
+      }
       // prototypical behavior
       this._configureProperties(this.properties, config);
       // override local configuration with configuration from above