System.Uri.Uri.GetLeftPart C# (CSharp) Method

		public string GetLeftPart (UriPartial part) 
		{
			EnsureAbsoluteUri ();
			int defaultPort;
			switch (part) {				
			case UriPartial.Scheme : 
				return scheme + GetOpaqueWiseSchemeDelimiter ();
			case UriPartial.Authority :
				if ((scheme == Uri.UriSchemeMailto) || (scheme == Uri.UriSchemeNews))
					return String.Empty;
					
				StringBuilder s = new StringBuilder ();
				s.Append (scheme);
				s.Append (GetOpaqueWiseSchemeDelimiter ());
				if (path.Length > 1 && path [1] == ':' && (Uri.UriSchemeFile == scheme)) 
					s.Append ('/');  // win32 file
				if (userinfo.Length > 0) 
					s.Append (userinfo).Append ('@');
				s.Append (host);
				defaultPort = GetDefaultPort (scheme);
				if ((port != -1) && (port != defaultPort))
					s.Append (':').Append (port);			 
				return s.ToString ();				
			case UriPartial.Path :
				StringBuilder sb = new StringBuilder ();
				sb.Append (scheme);
				sb.Append (GetOpaqueWiseSchemeDelimiter ());
				if (path.Length > 1 && path [1] == ':' && (Uri.UriSchemeFile == scheme)) 
					sb.Append ('/');  // win32 file
				if (userinfo.Length > 0) 
					sb.Append (userinfo).Append ('@');
				sb.Append (host);
				defaultPort = GetDefaultPort (scheme);
				if ((port != -1) && (port != defaultPort))
					sb.Append (':').Append (port);

				if (path.Length > 0) {
#if NET_2_0
					switch (Scheme) {
					case "mailto":
					case "news":
						sb.Append (path);
						break;
					default:
						sb.Append (Reduce (path, CompactEscaped (Scheme)));
						break;
					}
#else
					sb.Append (path);
#endif
				}
				return sb.ToString ();
			}
			return null;
		}