code: def _init_client_authentication(
              self,
              client_certchain_file: Optional[str],
              client_key_file: Optional[str],
              client_key_type: OpenSslFileTypeEnum,
              client_key_password: str,
              ignore_client_authentication_requests: bool
      ) -> None:
          
          if client_certchain_file is not None and client_key_file is not None:
              self._use_private_key(client_certchain_file, client_key_file, client_key_type, client_key_password)
  
          if ignore_client_authentication_requests:
              if client_certchain_file:
                  raise ValueError('Cannot enable both client_certchain_file and ignore_client_authentication_requests')
  
              self._ssl_ctx.set_client_cert_cb_NULL()
docs: Setup client authentication using the supplied certificate and key.