public void increOwnershipSize(Author author) {        
                Iterator<Author> itr = ownerships.keySet().iterator();
                Author existAuthor;
        
                
                while(itr.hasNext()) {
                        existAuthor = (Author) itr.next();
                        if(existAuthor.getEmailAddr().equals(author.getEmailAddr())) {
                                ownerships.put(existAuthor, ownerships.get(existAuthor) + 1);
                                return;
                        }
                }
                adjustOwnership(author, 1);
        }