Init logger.

def init_logger(self):
        """Init logger."""

        if not self.result_logger:
            if not os.path.exists(self.local_dir):
                os.makedirs(self.local_dir)
            if not self.logdir:
                self.logdir = tempfile.mkdtemp(
                    prefix="{}_{}".format(
                        str(self)[:MAX_LEN_IDENTIFIER], date_str()),
                    dir=self.local_dir)
            elif not os.path.exists(self.logdir):
                os.makedirs(self.logdir)

            self.result_logger = UnifiedLogger(
                self.config,
                self.logdir,
                upload_uri=self.upload_dir,
                loggers=self.loggers,
                sync_function=self.sync_function)