using a cached reference to hasOwnProperty (again)

underscore.js

@@ -26,7 +26,8 @@
   // Create quick reference variables for speed access to core prototypes.
   var slice            = ArrayProto.slice,
       unshift          = ArrayProto.unshift,
-      toString         = ObjProto.toString;
+      toString         = ObjProto.toString,
+      hasOwnProperty   = ObjProto.hasOwnProperty;
 
   // All **ECMAScript 5** native function implementations that we hope to use
   // are declared here.
@@ -839,7 +840,7 @@
 
   // Has own property?
   _.has = function(obj, key) {
-    return ObjProto.hasOwnProperty.call(obj, key);
+    return hasOwnProperty.call(obj, key);
   };
 
   // Utility Functions