private bool IsExterior(ElementType wallType)
        {
            Parameter    wallFunction = wallType.get_Parameter(BuiltInParameter.FUNCTION_PARAM);
            WallFunction value        = (WallFunction)wallFunction.AsInteger();

            return(value == WallFunction.Exterior);
        }
        public bool IsExterior(WallType wallType)
        {
            Parameter p = wallType.get_Parameter(
                BuiltInParameter.FUNCTION_PARAM);

            Debug.Assert(null != p, "expected wall type "
                         + "to have wall function parameter");

            WallFunction f = (WallFunction)p.AsInteger();

            return(WallFunction.Exterior == f);
        }