code: private void validateDefaultAccelerator(ZapMenuItem zme) {
  		KeyStroke ks = zme.getDefaultAccelerator();
  		if (ks == null) {
  			return;
  		}
  
  		if (isIdentifierWithDuplicatedAccelerator(zme.getIdentifier())) {
  			return;
  		}
  
  		for (Object obj : map.values()) {
  			KeyboardMapping km = (KeyboardMapping) obj;
  			if (isIdentifierWithDuplicatedAccelerator(km.getIdentifier())) {
  				continue;
  			}
  
  			if (hasSameDefaultAccelerator(km, ks) && !zme.getIdentifier().equals(km.getIdentifier())) {
  				String msg = String.format(
  						"Menus %s and %s use the same default accelerator: %s",
  						zme.getIdentifier(),
  						km.getIdentifier(),
  						ks);
  				logger.log(Constant.isDevMode() ? Level.ERROR : Level.WARN, msg);
  				if (menusDupDefaultAccelerator == null) {
  					menusDupDefaultAccelerator = new ArrayList<>();
  				}
  				menusDupDefaultAccelerator.add(zme.getIdentifier());
  				if (zme.getDefaultAccelerator().equals(zme.getAccelerator())) {
  					zme.setAccelerator(null);
  				}
  			}
  		}
  	}
docs: Validates that the given menu item does not have a duplicated default accelerator.
  <p>
  Duplicated default accelerators are ignored when configuring the menus.
  
  @param zme the menu item to validate.
  @see #menusDupDefaultAccelerator