System.Net.HttpWebRequest.HttpWebRequest.AddRange C# (CSharp) Method

		void AddRange (string rangeSpecifier, long range)
		{
			if (rangeSpecifier == null)
				throw new ArgumentNullException ("rangeSpecifier");
			if (!WebHeaderCollection.IsHeaderValue (rangeSpecifier))
				throw new ArgumentException ("Invalid range specifier", "rangeSpecifier");

			string r = webHeaders ["Range"];
			if (r == null)
				r = rangeSpecifier + "=";
			else {
				string old_specifier = r.Substring (0, r.IndexOf ('='));
				if (String.Compare (old_specifier, rangeSpecifier, StringComparison.OrdinalIgnoreCase) != 0)
					throw new InvalidOperationException ("A different range specifier is already in use");
				r += ",";
			}

			string n = range.ToString (CultureInfo.InvariantCulture);
			if (range < 0)
				r = r + "0" + n;
			else
				r = r + n + "-";
			webHeaders.RemoveAndAdd ("Range", r);
		}