code: def test_dist_feature_lookup():
      cpu_tensor0 = torch.cat(
          [torch.ones(128, 1024), torch.ones(128, 1024) * 2]
      )
      cpu_tensor1 = torch.cat(
          [torch.zeros(128, 1024), torch.zeros(128, 1024)]
      )
  
      # Global node IDs:
      global_id0 = torch.arange(128 * 2)
      global_id1 = torch.arange(128 * 2) + 128 * 2
  
      # Set the partition book for two features (partition 0 and 1):
      partition_book = torch.cat(
          [
              torch.zeros(128 * 2, dtype=torch.long),
              torch.ones(128 * 2, dtype=torch.long),
          ]
      )
  
      # Put the test tensor into the different feature stores with IDs:
      feature0 = LocalFeatureStore()
      feature0.put_global_id(global_id0, group_name=None)
      feature0.put_tensor(cpu_tensor0, group_name=None, attr_name="x")
  
      feature1 = LocalFeatureStore()
      feature1.put_global_id(global_id1, group_name=None)
      feature1.put_tensor(cpu_tensor1, group_name=None, attr_name="x")
  
      mp_context = torch.multiprocessing.get_context("spawn")
      with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
          sock.settimeout(1)
          sock.bind(("127.0.0.1", 0))
          port = sock.getsockname()[1]
  
      w0 = mp_context.Process(
          target=run_rpc_feature_test,
          args=(2, 0, feature0, partition_book, port),
      )
      w1 = mp_context.Process(
          target=run_rpc_feature_test,
          args=(2, 1, feature1, partition_book, port),
      )
  
      w0.start()
      w1.start()
      w0.join()
      w1.join()
  
file_path: pytorch_geometric/test/distributed/test_rpc.py
imports: import socket
  import torch
  import torch_geometric.distributed.rpc
  from torch_geometric.distributed import LocalFeatureStore
  from torch_geometric.distributed.dist_context import DistContext
  from torch_geometric.distributed.rpc import RPCRouter
  from torch_geometric.testing import onlyLinux
label_desc: Use image node_id 2 for calling a global function with example usage: test_dist_feature_lookup() without return types