code: def test_precision(self):
      # not looping results in a useful stack trace upon failure
      self.do_precision(np.half, np.single)
      self.do_precision(np.half, np.double)
      self.do_precision(np.single, np.double)
  
imports: import functools
  from unittest import expectedFailure, skipIf
  from pytest import raises
  from torch.testing._internal.common_utils import instantiate_parametrized_tests, parametrize, run_tests, slowTest, TEST_WITH_TORCHDYNAMO, TestCase, xpassIfTorchDynamo
label_desc: Use image node_id 28 for calling the TestHistogram obj's underlying member method code with example usage: obj.test_precision() without return types