Bug 49182 What should canceling setRawClasspath do ?
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/BuildPathsPropertyPage.java
String title= PreferencesMessages.getString("BuildPathsPropertyPage.error.title"); 
				String message= PreferencesMessages.getString("BuildPathsPropertyPage.error.message"); 
				ExceptionHandler.handle(e, shell, title, message);
				return false;
			} catch (InterruptedException e) {
				
				return false;
			}
		}
		return true;
	}
	
	/* (non-Javadoc)
	 * @see IStatusChangeListener#statusChanged
	 */
	public void statusChanged(IStatus status) {
		setValid(!status.matches(IStatus.ERROR));
		StatusUtil.applyToStatusLine(this, status);
	}
	/* (non-Javadoc)
	 * @see org.eclipse.jface.preference.IPreferencePage#performCancel()
	 */
	public boolean performCancel() {
		if (fBuildPathsBlock != null) {
			getSettings().put(INDEX, fBuildPathsBlock.getPageIndex());
		}
		return super.performCancel();
	}
}