docs: private static List<String> _evaluateValueExpressions(FacesContext context, List<String> values)
      {
          // note that we have to create a new List here, because if we
          // change any value on the given List, it will be changed in the
          // NavigationCase too and the EL expression won't be evaluated again
          List<String> target = new ArrayList<String>(values.size());
          for (String value : values)
          {
              if (_isExpression(value))
              {
                  // evaluate the ValueExpression
                  value = context.getApplication().evaluateExpressionGet(context, value, String.class);
              }
              target.add(value);
          }
          return target;
      }