if (set != null) {
Iterator valueIterator = set.iterator();
while (valueIterator.hasNext()) {
Drawing drawing = (Drawing) valueIterator.next();
store.store(bufferStream, drawing);
ZipEntry drawingEntry = new ZipEntry(id + "\\"
+ drawing.getTitle() + ".draw");
zipOutStream.putNextEntry(drawingEntry);
bufferStream.writeTo(zipOutStream);
zipOutStream.closeEntry();