Superclass of exceptions which indicate that an unknown kind of entity was encountered. This situation can occur if the language evolves and new kinds of constructs are introduced. Subclasses of this exception may be thrown by visitors to indicate that the visitor was created for a prior version of the language.
A common superclass for those exceptions allows a single catch block to have code handling them uniformly.
extends
javax.lang.model.element.UnknownElementException, javax.lang.model.element.UnknownAnnotationValueException, javax.lang.model.type.UnknownTypeException