BitServer.Program.check C# (CSharp) Method

        protected static string check(string raw)
        {
            if (raw.Contains(":"))
            {
                raw = raw.Split(':')[1].Trim();
            }
            if (raw.Contains("<") && raw.Contains(">"))
            {
                raw = raw.Substring(raw.LastIndexOf('<') + 1);
                raw = raw.Substring(0, raw.IndexOf('>'));
            }
            if (raw.ToLower().EndsWith("@" + EXTENSION))
            {
                return raw.Substring(0, raw.IndexOf('@'));
            }
            return null;
        }