code: public ICUResourceBundle getWithFallback(String path) throws MissingResourceException {
          ICUResourceBundle actualBundle = this;
  
          // now recurse to pick up sub levels of the items
          ICUResourceBundle result = findResourceWithFallback(path, actualBundle, null);
  
          if (result == null) {
              throw new MissingResourceException(
                  "Can't find resource for bundle "
                  + this.getClass().getName() + ", key " + getType(),
                  path, getKey());
          }
  
          if (result.getType() == STRING && result.getString().equals(NO_INHERITANCE_MARKER)) {
              throw new MissingResourceException("Encountered NO_INHERITANCE_MARKER", path, getKey());
          }
  
          return result;
      }
docs: This method performs multilevel fallback for fetching items from the
  bundle e.g: If resource is in the form de__PHONEBOOK{ collations{
  default{ "phonebook"} } } If the value of "default" key needs to be
  accessed, then do: <code>
  UResourceBundle bundle = UResourceBundle.getBundleInstance("de__PHONEBOOK");
  ICUResourceBundle result = null;
  if(bundle instanceof ICUResourceBundle){
  result = ((ICUResourceBundle) bundle).getWithFallback("collations/default");
  }
  </code>
  
  @param path The path to the required resource key
  @return resource represented by the key
  @exception MissingResourceException If a resource was not found.