Refactored defineProperty() code into define_secure_prop() function to reduce duplicate code

lib/class.js

@@ -226,6 +226,38 @@ function setup_props( func, class_data )
 }
 
 
+/**
+ * Attempts to define a non-enumerable, non-writable and non-configurable
+ * property on the given object
+ *
+ * If the operation is unsupported, a normal property will be set.
+ *
+ * @param  {Object}  obj    object to set property on
+ * @param  {string}  prop   name of property to set
+ * @param  {mixed}   value  value to set
+ *
+ * @return  {undefined}
+ */
+function define_secure_prop( obj, prop, value )
+{
+    if ( Object.defineProperty === undefined )
+    {
+        func[ prop ] = value;
+    }
+    else
+    {
+        Object.defineProperty( obj, prop,
+        {
+            value: value,
+
+            enumerable:   false,
+            writable:     false,
+            configurable: false,
+        });
+    }
+}
+
+
 /**
  * Attaches isAbstract() method to the class
  *
@@ -251,21 +283,7 @@ function attach_abstract( func, methods )
 
 
     // attach the list of abstract methods to the class
-    if ( Object.defineProperty === undefined )
-    {
-        func.abstractMethods = methods;
-    }
-    else
-    {
-        Object.defineProperty( func, 'abstractMethods',
-        {
-            value: methods,
-
-            enumerable:   false,
-            writable:     false,
-            configurable: false,
-        });
-    }
+    define_secure_prop( func, 'abstractMethods', methods );
 }
 
 
@@ -295,19 +313,5 @@ function attach_extend( func )
 
     // if defineProperty is unsupported, do it the old fashioned way (it's just
     // less restrictive)
-    if ( Object.defineProperty === undefined )
-    {
-        func.extend = ext_method;
-    }
-    else
-    {
-        Object.defineProperty( func, 'extend',
-        {
-            value: ext_method,
-
-            enumerable:   false,
-            writable:     false,
-            configurable: false,
-        } );
-    }
+    define_secure_prop( func, 'extend', ext_method );
 }