code: def test_mv_proposal(self):
      np.random.seed(42)
      cov = np.random.randn(5, 5)
      cov = cov.dot(cov.T)
      prop = MultivariateNormalProposal(cov)
      samples = np.array([prop() for _ in range(10000)])
      npt.assert_allclose(np.cov(samples.T), cov, rtol=0.2)
  
imports: import warnings
  import arviz
  import numpy
  import numpy.testing
  import pytensor
  import pytest
  import pymc
  from pymc.step_methods.metropolis import BinaryGibbsMetropolis, CategoricalGibbsMetropolis, DEMetropolis, DEMetropolisZ, Metropolis, MultivariateNormalProposal, NormalProposal
  from pymc.testing import fast_unstable_sampling_mode
  from tests import sampler_fixtures
  from tests.helpers import RVsAssignmentStepsTester, StepMethodTester
  from tests.models import mv_simple, mv_simple_discrete, simple_categorical
label_desc: Use image node_id 2 for calling the TestMetropolis obj's underlying member method code with example usage: obj.test_mv_proposal() without return types