code: def _assert_structural_equal(a, b):
      """Check structural equality of two Relay expressions."""
      reason = (
          "Actual and expected relay functions are not equal. "
          "IdentityOptimizer is not correctly removing redundant "
          "identity operations."
      )
      assert tvm.ir.structural_equal(a, b), reason
  
imports: import pytest
  import tensorflow
  import tvm
  from tvm import relay
  from tvm.relay.op.contrib.ethosu import partition_for_ethosu
  from tvm.relay.backend.contrib.ethosu.codegen import relay_to_tir
  from tvm.relay.backend.contrib.ethosu.codegen import IdentityOptimizer
  from .None import infra
label_desc: Use image node_id 2 for calling a global function with example usage: _assert_structural_equal(a, b) without return types