code: def certfile(self, certfile):
      if self._server_side and not certfile:
          raise ValueError("certfile is needed for server-side")
      if certfile and not os.access(certfile, os.R_OK):
          raise IOError("No such certfile found: %s" % (certfile))
      self._certfile = certfile
  
imports: import logging
  import os
  import socket
  import ssl
  import sys
  import warnings
  from .sslcompat import _match_hostname, _match_has_ipaddress
  from thrift.transport import TSocket
  from thrift.transport.TTransport import TTransportException
label_desc: Use image node_id 10 for calling the TSSLBase obj's underlying member method code with example usage: obj.certfile(certfile) without return types