code: def test_5_2_forward(self):
      nu = 5 / 2
      batch_size = (3, 2, 4)
      x1 = torch.randn(*batch_size, 7, 9)
      x2 = torch.randn(*batch_size, 6, 9)
      # Doesn't support ARD
      lengthscale = (
          torch.randn(*batch_size).view(*batch_size, 1, 1) ** 2
      )
  
      res = gpytorch.functions.MaternCovariance.apply(
          x1, x2, lengthscale, nu, dist_func
      )
      scaled_unitless_dist = math.sqrt(nu * 2) * dist_func(x1, x2).div(
          lengthscale
      )
      exp_component = torch.exp(-scaled_unitless_dist)
      actual = exp_component * (
          1 + scaled_unitless_dist + scaled_unitless_dist**2 / 3
      )
      self.assertTrue(torch.allclose(res, actual))
  
file_path: gpytorch/test/functions/test_matern_covariance.py
imports: import math
  import unittest
  import torch
  import gpytorch
label_desc: Use image node_id 5 for calling the TestMaternCovariance obj's underlying member method code with example usage: obj.test_5_2_forward() without return types