code: def _get_server_certificate(addr, ssl_version=PROTOCOL_SSLv23, ca_certs=None):
      
  
      if ssl_version not in (PROTOCOL_DTLS, PROTOCOL_DTLSv1, PROTOCOL_DTLSv1_2):
          return _orig_get_server_certificate(addr, ssl_version, ca_certs)
  
      if ca_certs is not None:
          cert_reqs = ssl.CERT_REQUIRED
      else:
          cert_reqs = ssl.CERT_NONE
      af = getaddrinfo(addr[0], addr[1])[0][0]
      s = ssl.wrap_socket(socket(af, SOCK_DGRAM),
                          ssl_version=ssl_version,
                          cert_reqs=cert_reqs, ca_certs=ca_certs)
      s.connect(addr)
      dercert = s.getpeercert(True)
      s.close()
      return ssl.DER_cert_to_PEM_cert(dercert)
docs: Retrieve a server certificate
  
      Retrieve the certificate from the server at the specified address,
      and return it as a PEM-encoded string.
      If 'ca_certs' is specified, validate the server cert against it.
      If 'ssl_version' is specified, use it in the connection attempt.