docstr: Checks if the host is in the blacklist.
docstr_tok: ["Checks","if","the","host","is","in","the","blacklist","."]
code: def is_blacklisted(self):
      """Checks if the host is in the blacklist."""
      return self._blacklisted
  
imports: import io
  import logging
  import random
  import threading
  import time
  from collections import defaultdict
  from horovod.runner.common.util import safe_shell_exec
  from horovod.runner.elastic.worker import HostUpdateResult
label_desc: Use image node_id 9 for calling the HostState obj's underlying member method code with example usage: obj.is_blacklisted() and returns: self