code: def test_emcee_init_with_chain(self):
      # can you initialise with a previous chain
      if not HAS_EMCEE:
          return True
  
      out = self.mini.emcee(nwalkers=100, steps=5)
      # can initialise with a chain
      self.mini.emcee(nwalkers=100, steps=1, pos=out.chain)
      # can initialise with a correct subset of a chain
      self.mini.emcee(nwalkers=100, steps=1, pos=out.chain[-1, ...])
  
      # but you can't initialise if the shape is wrong.
      pytest.raises(
          ValueError,
          self.mini.emcee,
          nwalkers=100,
          steps=1,
          pos=out.chain[-1, :-1, ...],
      )
  
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 13 for calling the CommonMinimizerTest obj's underlying member method code with example usage: obj.test_emcee_init_with_chain() and returns: True