code: def test_constraint_by_name(self):
      likelihood = gpytorch.likelihoods.GaussianLikelihood()
      model = ExactGPModel(None, None, likelihood)
  
      constraint = model.constraint_for_parameter_name(
          "likelihood.noise_covar.raw_noise"
      )
      self.assertIsInstance(
          constraint, gpytorch.constraints.GreaterThan
      )
  
      constraint = model.constraint_for_parameter_name(
          "covar_module.base_kernel.raw_lengthscale"
      )
      self.assertIsInstance(constraint, gpytorch.constraints.Positive)
  
      constraint = model.constraint_for_parameter_name(
          "mean_module.constant"
      )
      self.assertIsNone(constraint)
  
imports: import math
  import unittest
  import torch
  from torch import sigmoid
  from torch.nn.functional import softplus
  import gpytorch
  from gpytorch.test.base_test_case import BaseTestCase
label_desc: Use image node_id 1 for calling the TestConstraintNaming obj's underlying member method code with example usage: obj.test_constraint_by_name() without return types