code: def test_no_identity():
      """Check the graph is not affected when there is no identity in the graph."""
  
      def get_graph():
          dtype = "int8"
  
          x = relay.var("x", shape=(1, 2, 2, 4), dtype=dtype)
          x = infra.make_ethosu_conv2d(
              x, 4, 4, (1, 1), (0, 0), (1, 1), (1, 1)
          )
          x = infra.make_ethosu_pooling(
              x, "MAX", (1, 1), 4, dtype, (1, 1), (0, 0)
          )
          x = infra.make_ethosu_depthwise_conv2d(
              x, 4, (1, 1), (0, 0), (1, 1), (1, 1)
          )
          x = infra.make_ethosu_unary_elementwise(x, 4, "ABS")
          return relay.Function(relay.analysis.free_vars(x), x)
  
      actual = _optimize(get_graph())
      expected = _optimize(get_graph(), optimize=False)
      _assert_structural_equal(actual, expected)
  
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 5 for calling a global function with example usage: test_no_identity() and returns: relay