/// <summary>
        /// 撤回用户的OBS桶扩展权限。
        /// </summary>
        /// <param name="domainId">用户的domainId。</param>
        /// <param name="extensionPermissionEnum">OBS扩展权限。</param>
        public void WithDrawExtensionPermission(string domainId, ExtensionBucketPermissionEnum extensionPermissionEnum)
        {
            if (string.IsNullOrEmpty(domainId))
            {
                return;
            }

            IList <string> domainIds;

            ExtensionPermissionMap.TryGetValue(extensionPermissionEnum, out domainIds);
            domainId = domainId.Trim();
            if (domainIds != null && domainIds.Contains(domainId))
            {
                domainIds.Remove(domainId);
            }
        }
        /// <summary>
        /// 为用户授予OBS桶扩展权限。
        /// </summary>
        /// <param name="domainId">用户的domainId。</param>
        /// <param name="extensionPermissionEnum">OBS扩展权限。</param>
        public void GrantExtensionPermission(string domainId, ExtensionBucketPermissionEnum extensionPermissionEnum)
        {
            if (string.IsNullOrEmpty(domainId))
            {
                return;
            }

            IList <string> domainIds;

            ExtensionPermissionMap.TryGetValue(extensionPermissionEnum, out domainIds);

            if (domainIds == null)
            {
                domainIds = new List <string>();
                ExtensionPermissionMap.Add(extensionPermissionEnum, domainIds);
            }
            domainId = domainId.Trim();
            if (!domainIds.Contains(domainId))
            {
                domainIds.Add(domainId);
            }
        }