code: public static List<String> extractParameterNames(Serializable lambda, int lambdaParametersCount) {
          SerializedLambda serializedLambda = serialized(lambda);
  
          Method lambdaMethod = lambdaMethod(serializedLambda);
          String[] paramNames = paramNameReader.getParamNames(lambdaMethod);
          return asList(Arrays.copyOfRange(paramNames, paramNames.length - lambdaParametersCount, paramNames.length));
      }
docs: Extracts names of a serializable lambda parameters
  
  @param lambda                Serializable lambda
  @param lambdaParametersCount number of lambda parameters