code: def test_edge_cases(self):
      # Difficult edge cases for optimization
      self.optimize_compare("eb,cb,fb->cef")
      self.optimize_compare("dd,fb,be,cdb->cef")
      self.optimize_compare("bca,cdb,dbf,afc->")
      self.optimize_compare("dcc,fce,ea,dbf->ab")
      self.optimize_compare("fdf,cdd,ccd,afe->ae")
      self.optimize_compare("abcd,ad")
      self.optimize_compare("ed,fcd,ff,bcf->be")
      self.optimize_compare("baa,dcf,af,cde->be")
      self.optimize_compare("bd,db,eac->ace")
      self.optimize_compare("fff,fae,bef,def->abd")
      self.optimize_compare("efc,dbc,acf,fd->abe")
      self.optimize_compare("ba,ac,da->bcd")
  
imports: import functools
  import itertools
  from unittest import expectedFailure, skipIf, SkipTest
  import torch._numpy
  from pytest import raises
  from torch._numpy.testing import assert_, assert_allclose, assert_almost_equal, assert_array_equal, assert_equal, suppress_warnings
  from torch.testing._internal.common_utils import instantiate_parametrized_tests, parametrize, run_tests, TestCase
label_desc: Use image node_id 30 for calling the TestEinsum obj's underlying member method code with example usage: obj.test_edge_cases() without return types