Bug 182190 [StatusHandling] [Wizards] getControl assert on wizard page has no message
M6 If you forget to set the control on your wizard page our assert gives no feedback. We need an error message.
bundles/org.eclipse.jface/src/org/eclipse/jface/wizard/WizardDialog.java
}
        }
        return savedState;
    }
    /**
     * The Back button has been pressed.
     */
    protected void backPressed() {
        IWizardPage page = currentPage.getPreviousPage();
        if (page == null) {
			
            return;
		}
        
        isMovingToPreviousPage = true;
        
        showPage(page);
    }
    /* (non-Javadoc)
     * Method declared on Dialog.
     */
    protected void buttonPressed(int buttonId) {
        switch (buttonId) {
        case IDialogConstants.HELP_ID: {
            helpPressed();
            break;
        }
        case IDialogConstants.BACK_ID: {
            backPressed();
            break;