docstr: Test getting the machine id from /var/lib/dbus
docstr_tok: ["Test","getting","the","machine","id","from","\/var\/lib\/dbus"]
code: def test_machine_id_v3_from_dbus(self):
      """Test getting the machine id from /var/lib/dbus"""
      file_data = "dbus"
  
      with patch(
          "streamlit.runtime.metrics_util.uuid.getnode",
          return_value=MAC,
      ), patch(
          "streamlit.runtime.metrics_util.open",
          mock_open(read_data=file_data),
          create=True,
      ), patch(
          "streamlit.runtime.metrics_util.os.path.isfile",
          side_effect=lambda path: path == "/var/lib/dbus/machine-id",
      ):
          machine_id = metrics_util._get_machine_id_v3()
      self.assertEqual(machine_id, file_data)
  
imports: import contextlib
  import datetime
  import unittest
  from collections import Counter
  from typing import Any, Callable
  from unittest.mock import MagicMock, mock_open, patch
  import pandas
  from parameterized import parameterized
  import streamlit
  import streamlit.components.v1
  from streamlit.connections import SnowparkConnection, SQLConnection
  from streamlit.runtime import metrics_util
  from streamlit.runtime.caching import cache_data_api, cache_resource_api
  from streamlit.runtime.legacy_caching import caching
  from streamlit.runtime.scriptrunner import get_script_run_ctx, magic_funcs
  from streamlit.web.server import websocket_headers
  from tests.delta_generator_test_case import DeltaGeneratorTestCase
label_desc: Use image node_id 4 for calling the MetricsUtilTest obj's underlying member method code with example usage: obj.test_machine_id_v3_from_dbus() without return types