code: @Override
      public List<T> returnItemsWithState(final List<Integer> states) {
          if (states == null) throw new IllegalArgumentException("states cannot be null");
  
          final List<T> retValue = new ArrayList<T>();
  
          for (final V item : getItems()) {
              if (states.contains(item.getState())) retValue.add(item.getItem());
          }
  
          return retValue;
      }
docs: Get a collection of REST entities that have a particular state
  
  @param states Defines the list of states that an entity can be in to be returned
  @return A collection that holds all the REST entities included in the states collection