code: def tearDown(self):
      torch.set_default_dtype(self.prev_type)
  
imports: import unittest
  import torch
  from linear_operator.operators import CholLinearOperator, TriangularLinearOperator
  import gpytorch
  from gpytorch.constraints import GreaterThan
  from gpytorch.distributions import MultivariateNormal
  from gpytorch.variational import NaturalVariationalDistribution, TrilNaturalVariationalDistribution
label_desc: Use image node_id 2 for calling the Float64Test obj's underlying member method code with example usage: obj.tearDown() without return types