code: def test_no_blobs_error(self):
      sampler = emcee.EnsembleSampler(6, 1, lambda x: -(x**2))
      sampler.run_mcmc(np.random.normal(size=(6, 1)), 20)
      with pytest.raises(ValueError):
          from_emcee(sampler, blob_names=["inexistent"])
  
imports: import os
  import numpy
  import pytest
  from ...None import from_emcee
  from ..helpers import _emcee_lnprior
  from ..helpers import _emcee_lnprob
  from ..helpers import chains, check_multiple_attrs, draws, eight_schools_params, importorskip, load_cached_models, needs_emcee3_func
label_desc: Use image node_id 8 for calling the TestDataEmcee obj's underlying member method code with example usage: obj.test_no_blobs_error() without return types