code: def test_lamb(self):
      def lamb_constructor(params):
          return StochasticWeightAveraging(
              Lamb(params, weight_decay=0.01),
              swa_start=1000,
              swa_freq=1,
              swa_lr=1e-2,
          )
  
      self._test_rosenbrock(lamb_constructor, automode=False)
  
imports: import contextlib
  import functools
  import re
  import warnings
  from unittest import TestCase
  import torch
  from pytext.optimizer import Lamb, StochasticWeightAveraging
  from torch import nn, optim, sparse
  from torch.autograd import Variable
  from torch.utils import data
label_desc: Use image node_id 19 for calling the TestSWA obj's underlying member method code with example usage: obj.test_lamb() and returns: StochasticWeightAveraging