code: def exists_path(
      src: Instance.InstanceStatus,
      dst: Instance.InstanceStatus,
      graphs: Dict[
          "Instance.InstanceStatus", Set["Instance.InstanceStatus"]
      ],
  ) -> bool:
      # BFS search from src to dst to see if there is a path
      # from src to dst. There's no path if src == dst.
      visited = set()
      queue = [src]
      if src == dst:
          return False
      while queue:
          node = queue.pop(0)
          if node not in visited:
              visited.add(node)
              queue.extend(graphs[node])
      return dst in visited
  
file_path: ray/python/ray/autoscaler/v2/tests/test_instance_manager.py
imports: import os
  import sys
  import unittest
  from typing import Dict, Set
  from unittest.mock import patch
  import pytest
  from ray.autoscaler.v2.instance_manager.instance_manager import InstanceUtil
  from ray.autoscaler.v2.schema import InvalidInstanceStatusError
  from ray.core.generated.instance_manager_pb2 import Instance
label_desc: Use image node_id 1 for calling a global function with example usage: exists_path(src, dst, graphs) and returns: unknown, False