code: def test_ray_init_context(shutdown_only):
      ctx = ray.init()
      assert ray.is_initialized()
      # Check old context fields can be accessed like a dict
      assert ctx["session_dir"] is not None
      assert ctx["node_id"] is not None
      with pytest.raises(KeyError):
          ctx["xyz"]
      # Check that __contains__ works
      assert "session_dir" in ctx
      assert "abcdefg" not in ctx
      # Check that get works
      assert ctx.get("session_dir") is not None
      assert ctx.get("gfedcba") is None
      ctx.disconnect()
      assert not ray.is_initialized()
  
imports: import logging
  import os
  import sys
  import unittest.mock
  import tempfile
  import shutil
  from unittest.mock import patch
  import pytest
  import ray
  from ray._private.ray_constants import RAY_OVERRIDE_DASHBOARD_URL, DEFAULT_RESOURCES
  from ray.air.util.node import _get_node_id_from_node_ip
  import ray._private.services
  from ray._private.services import get_node_ip_address
  from ray.dashboard.utils import ray_address_to_api_server_url
  from ray._private.test_utils import get_current_unused_port, run_string_as_driver, wait_for_condition
  from ray.util.client.ray_client_helpers import ray_start_client_server
label_desc: Use image node_id 1 for calling a global function with example usage: test_ray_init_context(shutdown_only) without return types