下载文件
        :param remote_file:
        :param local_file:
        :return:

def get(self, remote_file, local_file):
        """
        下载文件
        :param remote_file:
        :param local_file:
        :return:
        """
        sftp = self.get_sftp()
        try:
            sftp.get(remote_file, local_file)
        except Exception as e:
            logger.error('下载文件失败')
            logger.error('remote: %s, local: %s' % (remote_file, local_file))
            logger.error(e)