code: def test_half_cauchy_prior_to_gpu(self):
      if torch.cuda.is_available():
          prior = HalfCauchy(1.0).cuda()
          self.assertEqual(prior.concentration.device.type, "cuda")
          self.assertEqual(prior.rate.device.type, "cuda")
  
file_path: gpytorch/test/priors/test_half_cauchy_prior.py
imports: import unittest
  import torch
  from torch.distributions import HalfCauchy
  from gpytorch.priors import HalfCauchyPrior
  from gpytorch.test.utils import least_used_cuda_device
label_desc: Use image node_id 1 for calling the TestHalfCauchyPrior obj's underlying member method code with example usage: obj.test_half_cauchy_prior_to_gpu() without return types