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
}
    /**
     * Closes this window.
     *
     * @return <code>true</code> if the window is (or was already) closed, 
     *   and <code>false</code> if it is still open
     */
    private boolean hardClose() {
        
        for (int i = 0; i < createdWizards.size(); i++) {
            IWizard createdWizard = (IWizard) createdWizards.get(i);
            createdWizard.dispose();
            
            
            
            
            createdWizard.setContainer(null);
        }
        return super.close();
    }
    /**
     * The Help button has been pressed.
     */
    protected void helpPressed() {
        if (currentPage != null) {
            currentPage.performHelp();
        }
    }
    /**
     * The Next button has been pressed.