Error extension that includes error status codes from the WebDriver wire protocol: http://code.google.com/p/selenium/wiki/JsonWireProtocol#Response_Status_Codes
The error's status code.
Optional error message.
This error's status code.
Flag used for duck-typing when this code is embedded in a Firefox extension. This is required since an Error thrown in one component and then reported to another will fail instanceof checks in the second component.
string
The string representation of this error.