code: def _test_forward(self, batch_size):
      # create model
      config = FreeVCConfig()
      model = FreeVC(config).to(device)
      model.train()
      print(
          " > Num parameters for FreeVC model:%s"
          % (count_parameters(model))
      )
  
      _, _, mel, spec, spec_lengths, waveform = self._create_inputs(
          config, batch_size
      )
  
      wavlm_vec = model.extract_wavlm_features(waveform)
      wavlm_vec_lengths = torch.ones(batch_size, dtype=torch.long)
  
      y = model.forward(
          wavlm_vec, spec, None, mel, spec_lengths, wavlm_vec_lengths
      )
  
imports: import os
  import unittest
  import torch
  from tests import get_tests_input_path
  from TTS.vc.configs.freevc_config import FreeVCConfig
  from TTS.vc.models.freevc import FreeVC
label_desc: Use image node_id 6 for calling the TestFreeVC obj's underlying member method code with example usage: obj._test_forward(batch_size) without return types