if (blip != null) {
String blipId1 = blip.getId();
EventGeneratingDocumentHandler docHandler = docHandlers.get(blipId1);
if (docHandler == null) {
ObservableDocument doc = (ObservableDocument) blip.getContent();
docHandler = new EventGeneratingDocumentHandler(
doc, blip, capabilities, messages, deltaAuthor, timestamp);
doc.addListener(docHandler);
docHandlers.put(blipId1, docHandler);
} else {
docHandler.setAuthorAndTimeStamp(deltaAuthor, timestamp);
}
}