public CachePolicy PublicClientCaching(DateTime expirationUtcTimestamp) { if (expirationUtcTimestamp.Kind != DateTimeKind.Utc) { throw new ArgumentException("Expiration must be UTC.", "expirationUtcTimestamp"); } _cacheability = HttpCacheability.Public; _clientCacheExpirationUtcTimestamp = expirationUtcTimestamp; _clientCacheMaxAge = null; _hasPolicy = true; return this; }