System.Net.Http.Headers.HttpGeneralHeaders.AddKnownHeaders C# (CSharp) Method

        internal static void AddKnownHeaders(HashSet<string> headerSet)
        {
            Debug.Assert(headerSet != null);

            headerSet.Add(HttpKnownHeaderNames.CacheControl);
            headerSet.Add(HttpKnownHeaderNames.Connection);
            headerSet.Add(HttpKnownHeaderNames.Date);
            headerSet.Add(HttpKnownHeaderNames.Pragma);
            headerSet.Add(HttpKnownHeaderNames.Trailer);
            headerSet.Add(HttpKnownHeaderNames.TransferEncoding);
            headerSet.Add(HttpKnownHeaderNames.Upgrade);
            headerSet.Add(HttpKnownHeaderNames.Via);
            headerSet.Add(HttpKnownHeaderNames.Warning);
        }

        private static HashSet <string> CreateInvalidHeaders()
        {
            var invalidHeaders = new HashSet <string>(StringComparer.OrdinalIgnoreCase);

            HttpRequestHeaders.AddKnownHeaders(invalidHeaders);
            HttpResponseHeaders.AddKnownHeaders(invalidHeaders);
            HttpGeneralHeaders.AddKnownHeaders(invalidHeaders);

            return(invalidHeaders);
        }