code: public Object getLambdaArgument(String arg) {
          if (lambdaArgs == null) {
              return null;
          }
  
          for (int i = lambdaArgs.size() - 1; i >= 0; i--) {
              Map<String, Object> lmap = lambdaArgs.elementAt(i);
              Object v = lmap.get(arg);
              if (v != null) {
                  return v;
              }
          }
          return null;
      }
docs: Retrieves the Lambda argument associated with a formal parameter.
  If the Lambda expression is nested within other Lambda expressions, the
  arguments for the current Lambda expression is first searched, and if
  not found, the arguments for the immediate nesting Lambda expression
  then searched, and so on.
  
  @param arg The formal parameter for the Lambda argument
  @return The object associated with formal parameter.  Null if
  no object has been associated with the parameter.
  @since EL 3.0