code: def test_slave_for_slave_not_found_error(cluster, sentinel):
      cluster.master["is_odown"] = True
      slave = sentinel.slave_for("mymaster", db=9)
      with pytest.raises(SlaveNotFoundError):
          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 15 for calling a global function with example usage: test_slave_for_slave_not_found_error(cluster, sentinel) without return types