code: def test_duplicate(self):
      with pytest.raises(ValueError):
          gpu_spec("A100:A100")
  
imports: import argparse
  from typing import List, Tuple
  import pytest
  from dstack._internal.cli.services.configurators.profile import apply_profile_args, gpu_spec, register_profile_args
  from dstack._internal.core.models.profiles import Profile, ProfileGPU, ProfileResources, ProfileRetryPolicy, SpotPolicy
label_desc: Use image node_id 8 for calling the TestGPUSpec obj's underlying member method code with example usage: obj.test_duplicate() without return types