code: public Object saveState(FacesContext context) {
  
          if (context == null) {
              throw new NullPointerException();
          }
          return new Object[] { methodExpressionOneArg, methodExpressionZeroArg  };
  
      }
docs: <p class="changed_modified_2_0">Both {@link MethodExpression}
  instances described in the constructor must be saved.</p>