System.Net.Cache.HttpRequestCacheValidator.ParseNameValues C# (CSharp) Method

        private string ParseNameValues(NameValueCollection cc, StringCollection sc, int start)
        {
            WebHeaderCollection wc = cc as WebHeaderCollection;

            string lastHeaderName = null;
            if (sc != null)
            {
                for (int i = start; i < sc.Count; ++i)
                {
                    string s = sc[i];
                    if (s == null || s.Length == 0)
                    {
                        //An empty string stands for \r\n
                        //Treat that as the end of headers and ignore the rest
                        return null;
                    }

                    if (s[0] == ' ' || s[0] == '\t')
                    {
                        if (lastHeaderName == null) {return s;}
                        if (wc != null)
                            wc.AddInternal(lastHeaderName, s);
                        else
                            cc.Add(lastHeaderName, s);
                    }

                    int colpos = s.IndexOf(':');
                    if (colpos < 0)
                        {return s;}
                    lastHeaderName = s.Substring(0, colpos);
                    while (++colpos < s.Length && (s[colpos] == ' ' || s[colpos] == '\t'))
                        {;}

                    try {
                        if (wc != null)
                            wc.AddInternal(lastHeaderName, s.Substring(colpos));
                        else
                            cc.Add(lastHeaderName, s.Substring(colpos));
                    }
                    catch(Exception e) {
                        if (e is ThreadAbortException || e is StackOverflowException || e is OutOfMemoryException)
                            throw;
                        // Otherwise the value of 's' will be used to log an error.
                        // The fact that we cannot parse headers may stand for corrupted metadata that we try to ignore
                        return s;
                    }
                }
            }
            return null;
        }
        //