code: def test_optimizer_basic(self):
      optimizer_params = Params({"type": "sgd", "lr": 1})
      parameters = [
          [n, p]
          for n, p in self.model.named_parameters()
          if p.requires_grad
      ]
      optimizer = Optimizer.from_params(
          model_parameters=parameters, params=optimizer_params
      )
      param_groups = optimizer.param_groups
      assert len(param_groups) == 1
      assert param_groups[0]["lr"] == 1
  
imports: import copy
  import re
  from allennlp.common.params import Params
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.data import Vocabulary
  from allennlp.data.dataset_readers import SequenceTaggingDatasetReader
  from allennlp.data.data_loaders import SimpleDataLoader
  from allennlp.models.simple_tagger import SimpleTagger
  from allennlp.training import GradientDescentTrainer
  from allennlp.training.optimizers import Optimizer
label_desc: Use image node_id 2 for calling the TestOptimizer obj's underlying member method code with example usage: obj.test_optimizer_basic() without return types