code: def _create_single_conv2d():
      ifm = relay.var("x", shape=(1, 8, 8, 4), dtype="int8")
      conv1 = test_infra.make_ethosu_conv2d(
          ifm, 4, 4, (3, 3), (1, 1), (1, 1), (1, 1)
      )
      func = relay.Function(relay.analysis.free_vars(conv1), conv1)
      return func
  
file_path: tvm/tests/python/contrib/test_ethosu/cascader/test_integration.py
imports: import pytest
  import numpy
  import tvm
  from tvm import relay
  from tvm.relay.backend.contrib.ethosu.codegen import _create_cascader
  from tvm.relay.backend.contrib.ethosu.tir.compiler import _lower_to_tir
  from tvm.contrib.ethosu.cascader import MemoryRegion, EthosuDeviceConfig
  from ..None import infra
  from .None import infra
label_desc: Use image node_id 3 for calling a global function with example usage: _create_single_conv2d() and returns: func