code: def test_add_connection(replica_list):
      replica_list.add_connection("executor0", "executor-0")
      assert replica_list.has_connections()
      assert replica_list.has_connection("executor0")
      assert not replica_list.has_connection("random-address")
      assert len(replica_list.get_all_connections()) == 1
  
file_path: jina/tests/unit/serve/networking/test_replica_list.py
imports: import asyncio
  import pytest
  from grpc import ChannelConnectivity
  from jina.serve.networking.connection_stub import _ConnectionStubs
  from jina.serve.networking.instrumentation import _NetworkingHistograms
  from jina.serve.networking.replica_list import _ReplicaList
label_desc: Use image node_id 2 for calling a global function with example usage: test_add_connection(replica_list) without return types