public void TestStringCategoryMessaging ()
{
// Create an object
IntPtr str = objc_sendMsg_IntPtr (this.cls_NSString, this.sel_string);
Assert.AreNotEqual (IntPtr.Zero, str, "NSString allocation failed");
uint count1 = objc_sendMsg_uint (str, sel_registerName ("length"));
uint count2 = objc_sendMsg_uint (str, sel_registerName ("retrieveLength"));
Assert.AreEqual (count1, count2, "Length must be equals");
}