A DESCRIPTION OF THE PROBLEM :
In the verbose description of SwingWorker's get() method there is an example starting with

class SwingWorkerCompletionWaiter extends PropertyChangeListener {

This code throws the error "no interface expected here" at compile time.
The line of code should read

class SwingWorkerCompletionWaiter IMPLEMENTS PropertyChangeListener {


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
class SwingWorkerCompletionWaiter implements PropertyChangeListener {
ACTUAL -
class SwingWorkerCompletionWaiter extends PropertyChangeListener {


URL OF FAULTY DOCUMENTATION :
http://docs.oracle.com/javase/8/docs/api/index.html