Indicates that a given class is not traversable and does
 intentionally not implement 
Traverseproc.
 This annotation is ignored if the class implements 
Traverseproc,
 i.e. it cannot be used to remove 
Traverseproc support of a
 superclass. Thus it is well defined what happens if both
 
Traverseproc and 
{@literal @}Untraversable
 are present: 
Traverseproc wins.
 If a class does not implement 
Traverseproc and is not
 annotated with 
{@literal @}Untraversable, gc assumes
 that the programmers were not aware of Jython's traverse
 mechanism and attempts to traverse the target object by using
 Java-reflection (which is assumably very inefficient).