A DESCRIPTION OF THE PROBLEM :
There is a typo in the method javadoc. It says 'mutatino' instead of 'mutation' ( "and still exist after the mutatino" ).

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
mutation
ACTUAL -
mutatino

URL OF FAULTY DOCUMENTATION :
http://java.sun.com/javase/6/docs/api/javax/swing/event/DocumentEvent.html#getChange(javax.swing.text.Element)