code: def test_virtual_device():
      nodes = [
          {"type_key": ""},
          {
              "type_key": "relay.Function",
              "attrs": {
                  "_checked_type_": "0",
                  "attrs": "0",
                  "body": "0",
                  "params": "0",
                  "ret_type": "0",
                  "span": "0",
                  "type_params": "0",
              },
          },
      ]
      data = {
          "root": 1,
          "nodes": nodes,
          "attrs": {"tvm_version": "0.8.0"},
          "b64ndarrays": [],
      }
      func = tvm.ir.load_json(json.dumps(data))
      assert isinstance(func, relay.Function)
      assert not func.virtual_device_
  
file_path: tvm/tests/python/relay/test_json_compact.py
imports: import tvm
  from tvm import relay
  from tvm import te
  import json
label_desc: Use image node_id 10 for calling a global function with example usage: test_virtual_device() without return types