code: def test_multitrace_iter_notimplemented(self):
      mtrace = base.MultiTrace([self.strace0])
      with pytest.raises(NotImplementedError):
          for _ in mtrace:
              pass
  
imports: import numpy
  import numpy.testing
  import pytest
  from pymc.backends import base, ndarray
  from tests.backends import fixtures
label_desc: Use image node_id 3 for calling the TestMultiTrace obj's underlying member method code with example usage: obj.test_multitrace_iter_notimplemented() without return types