writer := WriteOnClose(io.Discard)
	if writer.HasWritten() {
		t.Error("WriteOnCloser must not be marked as HasWritten")
	}
	writer.Write(nil)
	if !writer.HasWritten() {
		t.Error("WriteOnCloser must be marked as HasWritten")
	}

	writer = WriteOnClose(io.Discard)
	writer.Close()
	if !writer.HasWritten() {
		t.Error("WriteOnCloser must be marked as HasWritten")
	}
}

// Test for AppendFile.

// to the peer.
type WriteOnCloser struct {
	io.Writer
	hasWritten bool
}

func (w *WriteOnCloser) Write(p []byte) (int, error) {
	w.hasWritten = true
	return w.Writer.Write(p)
}

// Close closes the WriteOnCloser. It behaves like io.Closer.
func (w *WriteOnCloser) Close() error {
	if !w.hasWritten {
		_, err := w.Write(nil)
		if err != nil {
			return err
		}
	}

			if e != nil {
				return e
			}
			// Quote string...
			b, _ := json.Marshal(file.Name)
			if hasWritten {
				fmt.Print(",\n")
			}
			fmt.Printf("\t%s: ", string(b))

			b, e = decode(r, file.Name)
			if e != nil {
				return e
			}
			fmt.Print(string(b))
			hasWritten = true
		}
	}
	fmt.Println("")
	fmt.Println("}")

	return nil
}

var (

	if _, err = xioutil.Copy(httpWriter, rc); err != nil {
		if !httpWriter.HasWritten() {
			// write error response only if no data or headers has been written to client yet
			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
			return
		}
		return
	}

	if err = httpWriter.Close(); err != nil {
		if !httpWriter.HasWritten() { // write error response only if no data or headers has been written to client yet

	if _, err = xioutil.Copy(httpWriter, gr); err != nil {
		if !httpWriter.HasWritten() && !statusCodeWritten {
			// write error response only if no data or headers has been written to client yet
			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
			return
		}
		return
	}

	if err = httpWriter.Close(); err != nil {