code: def test_pretraining_and_evaluation(self) -> None:
      with in_temporary_directory():
          config = self._create_pretraining_config(
              with_mixed_precision=True, gpu_count=2, num_epochs=1
          )
          result = run_integration_test(config)
          ddp_losses = result.get_losses()
          self.assertGreater(len(ddp_losses), 0)
  
imports: import unittest
  from vissl.utils.hydra_config import compose_hydra_configuration, convert_to_attrdict
  from vissl.utils.test_utils import gpu_test, in_temporary_directory, run_integration_test
label_desc: Use image node_id 2 for calling the TestSwAV obj's underlying member method code with example usage: obj.test_pretraining_and_evaluation() without return types