er indicates
 that it is no longer able to reliably detect and report errors.  In these
 cases, the Jakarta XML Binding Provider will set the severity of the ValidationEvent to
 FATAL_ERROR to indicate that the unmarshal, validate, or marshal operations 
 should be terminated.  The default event handler and 
 <code>ValidationEventCollector</code> utility class must terminate processing
 after being notified of a fatal error.  Client applications that supply their 
 own <code>ValidationEventHandler</code> sh