code: def connection(self, host, port):
      connections.add_connection(default={"host": host, "port": port})
      connections.connect(alias="default")
  
      if connections.has_connection("default") is False:
          raise Exception("no connections")
      self.host = host
      self.port = port
      self.instance_name = get_milvus_instance_name(
          constants.CHAOS_NAMESPACE, host
      )
  
imports: import threading
  import pytest
  import time
  import random
  from pathlib import Path
  from time import sleep
  from pymilvus import connections
  from chaos.checker import InsertFlushChecker, SearchChecker, QueryChecker, Op
  from common.cus_resource_opts import CustomResourceOperations
  from common.milvus_sys import MilvusSys
  from utils.util_log import test_log
  from utils.util_k8s import wait_pods_ready, get_pod_ip_name_pairs, get_milvus_instance_name
  from chaos import chaos_commons
  from common.common_type import CaseLabel
  from common import common_func
  from chaos import constants
  from delayed_assert import expect, assert_expectations
label_desc: Use image node_id 1 for calling the TestChaos obj's underlying member method code with example usage: obj.connection(host, port) without return types