code: def test_emcee_output(self):
      # test mcmc output
      if not HAS_EMCEE:
          return True
      try:
          from pandas import DataFrame
      except ImportError:
          return True
      out = self.mini.emcee(nwalkers=10, steps=20, burn=5, thin=2)
      assert isinstance(out, MinimizerResult)
      assert isinstance(out.flatchain, DataFrame)
  
      # check that we can access the chains via parameter name
      # print( out.flatchain['amp'].shape[0],  200)
      assert out.flatchain["amp"].shape[0] == 70
      assert out.errorbars
      assert np.isfinite(out.params["amp"].correl["period"])
  
      # the lnprob array should be the same as the chain size
      assert np.size(out.chain) // out.nvarys == np.size(out.lnprob)
  
      # test chain output shapes
      print(out.lnprob.shape, out.chain.shape, out.flatchain.shape)
      assert out.lnprob.shape == (7, 10)
      assert out.chain.shape == (7, 10, 4)
      assert out.flatchain.shape == (70, 4)
  
imports: import sys
  import unittest
  import numpy
  from numpy import pi
  from numpy.testing import assert_allclose, assert_almost_equal, assert_equal
  import pytest
  from scipy.optimize import rosen_der
  from uncertainties import ufloat
  from lmfit import Minimizer, Parameters, minimize
  from lmfit.lineshapes import gaussian
  from lmfit.minimizer import HAS_EMCEE, SCALAR_METHODS, MinimizerResult, coerce_float64
  from lmfit.models import SineModel
label_desc: Use image node_id 16 for calling the CommonMinimizerTest obj's underlying member method code with example usage: obj.test_emcee_output() and returns: True, True