code: def test_shapes(
      backend, moves, nwalkers=32, ndim=3, nsteps=10, seed=1234
  ):
      # Set up the random number generator.
      np.random.seed(seed)
  
      with backend() as be:
          # Initialize the ensemble, moves and sampler.
          coords = np.random.randn(nwalkers, ndim)
          sampler = EnsembleSampler(
              nwalkers, ndim, normal_log_prob, moves=moves, backend=be
          )
  
          # Run the sampler.
          sampler.run_mcmc(coords, nsteps)
          chain = sampler.get_chain()
          assert len(chain) == nsteps, "wrong number of steps"
  
          tau = sampler.get_autocorr_time(quiet=True)
          assert tau.shape == (ndim,)
  
          # Check the shapes.
          with pytest.warns(DeprecationWarning):
              assert sampler.chain.shape == (
                  nwalkers,
                  nsteps,
                  ndim,
              ), "incorrect coordinate dimensions"
          with pytest.warns(DeprecationWarning):
              assert sampler.lnprobability.shape == (
                  nwalkers,
                  nsteps,
              ), "incorrect probability dimensions"
          assert sampler.get_chain().shape == (
              nsteps,
              nwalkers,
              ndim,
          ), "incorrect coordinate dimensions"
          assert sampler.get_log_prob().shape == (
              nsteps,
              nwalkers,
          ), "incorrect probability dimensions"
  
          assert sampler.acceptance_fraction.shape == (
              nwalkers,
          ), "incorrect acceptance fraction dimensions"
  
          # Check the shape of the flattened coords.
          assert sampler.get_chain(flat=True).shape == (
              nsteps * nwalkers,
              ndim,
          ), "incorrect coordinate dimensions"
          assert sampler.get_log_prob(flat=True).shape == (
              nsteps * nwalkers,
          ), "incorrect probability dimensions"
  
imports: import pickle
  from itertools import islice, product
  import numpy
  import pytest
  from emcee import EnsembleSampler, backends, moves, walkers_independent
label_desc: Use image node_id 2 for calling a global function with example usage: test_shapes(backend, moves, nwalkers, ndim, nsteps, seed) without return types