code: protected void fireStateChange(StreamState oldState, StreamState newState) {
          final PropertyChangeEvent evt = new PropertyChangeEvent(this, "StreamState", oldState, newState);
          for (PropertyChangeListener listener : stateListeners) {
              listener.propertyChange(evt);
          }
      }
docs: Creates a new {@link PropertyChangeEvent} and delivers it to all currently registered state listeners.
  
  @param oldState
  the {@link StreamState} we had before the change
  @param newState
  the {@link StreamState} we had after the change