docstr: Test perplexities of style-controlled generation models in the zoo.
docstr_tok: ["Test","perplexities","of","style-controlled","generation","models","in","the","zoo","."]
code: def test_perplexities(self):
      """
      Test perplexities of style-controlled generation models in the zoo.
      """
      test_cases = [("c75_labeled_dialogue_generator", 1.0, 7.664)]
      for model_name, style_frac, desired_ppl in test_cases:
          _, test = testing_utils.eval_model(
              opt={
                  "batchsize": 4,
                  "fp16": True,
                  "num_examples": 16,
                  "model_file": f"zoo:style_gen/{model_name}/model",
                  "model": "projects.style_gen.style_gen:StyleGenAgent",
                  "skip_generation": True,
                  "task": "style_gen:LabeledBlendedSkillTalk",
                  "use_style_frac": style_frac,
              },
              skip_valid=True,
          )
          self.assertAlmostEqual(test["ppl"], desired_ppl, delta=0.005)
  
file_path: ParlAI/tests/nightly/gpu/test_style_gen.py
imports: import unittest
  import parlai.utils.testing
  from parlai.core.opt import Opt
label_desc: Use image node_id 1 for calling the TestStyleGen obj's underlying member method code with example usage: obj.test_perplexities() without return types