code: def test_slave_for(cluster, sentinel):
      cluster.slaves = [
          {
              "ip": "127.0.0.1",
              "port": 6379,
              "is_odown": False,
              "is_sdown": False,
          }
      ]
      slave = sentinel.slave_for("mymaster", db=9)
      assert slave.ping()
  
imports: import socket
  from unittest import mock
  import pytest
  import redis.sentinel
  from redis import exceptions
  from redis.sentinel import MasterNotFoundError, Sentinel, SentinelConnectionPool, SlaveNotFoundError
label_desc: Use image node_id 14 for calling a global function with example usage: test_slave_for(cluster, sentinel) without return types