IronRuby.Builtins.RubyIO.CloseWriter C# (CSharp) Method

        public void CloseWriter() {
            var duplex = GetStream().BaseStream as DuplexStream;
            if (duplex == null && _mode.CanRead() || duplex != null && !_mode.CanWrite()) {
                throw RubyExceptions.CreateIOError("closing non-duplex IO for writing");
            }
            
            if (duplex != null) {
                duplex.Writer.Close();
            }

            _mode = _mode.CloseWrite();
            if (_mode.IsClosed()) {
                Close();
            }
        }

 public static void CloseWriter(RubyIO /*!*/ self)
 {
     if (self.Closed)
     {
         throw RubyExceptions.CreateIOError("closed stream");
     }
     self.CloseWriter();
 }