Java doesn't allow you to have null as an attribute value. It wants you to indicate what you really mean by null, so that is what we do here - as ugly as it is.
| Modifiers | Name | Description | 
|---|---|---|
| static class | Undefined.CLASS | |
| static class | Undefined.EXCEPTION | 
| Type Params | Return Type | Name and description | 
|---|---|---|
|  | static boolean | isUndefined(String other) | 
|  | static boolean | isUndefined(ClassNode other) | 
|  | static boolean | isUndefinedException(ClassNode other) |