public Perspective loadPerspectiveFile(InputStream istream) throws SalsaPerspectiveException {
try {
ObjectInputStream objectInputStream = new ObjectInputStream(istream);
return (Perspective) objectInputStream.readObject();
} catch (IOException e) {
throw new SalsaPerspectiveException(e.getMessage(), e);
} catch (ClassNotFoundException e) {
throw new SalsaPerspectiveException(e.getMessage(), e);
}
}