code: public static <T> List<T> createIfNull(List<T> currentValue) {
          if (currentValue == null) {
              return new ArrayList<T>();
          } else {
              return currentValue;
          }
      }
docs: Returns passed currentValue if it is not null and creates a new ArrayList if it is null.
  <br><br>
  Example: values = createIfNull(values)