code: def test_dist_iv(self):
      message = "`dist` must be an instance of..."
      with pytest.raises(ValueError, match=message):
          stats.fit(10, self.data, self.shape_bounds_a)
  
imports: import os
  import numpy
  import numpy.testing
  from numpy.testing import assert_allclose, assert_equal
  import pytest
  from scipy import stats
  from scipy.optimize import differential_evolution
  from .test_continuous_basic import distcont
  from scipy.stats._distn_infrastructure import FitError
  from scipy.stats._distr_params import distdiscrete
  from scipy.stats import goodness_of_fit
label_desc: Use image node_id 2 for calling the TestFit obj's underlying member method code with example usage: obj.test_dist_iv() without return types