code: def test_expand(self):
      # Outer products
      self.optimize_compare("ab,cd,ef->abcdef")
      self.optimize_compare("ab,cd,ef->acdf")
      self.optimize_compare("ab,cd,de->abcde")
      self.optimize_compare("ab,cd,de->be")
      self.optimize_compare("ab,bcd,cd->abcd")
      self.optimize_compare("ab,bcd,cd->abd")
  
imports: import itertools
  import sys
  import platform
  import pytest
  import numpy
  from numpy.testing import assert_, assert_equal, assert_array_equal, assert_almost_equal, assert_raises, suppress_warnings, assert_raises_regex, assert_allclose
label_desc: Use image node_id 37 for calling the TestEinsum obj's underlying member method code with example usage: obj.test_expand() without return types