src/main/java/org/jivesoftware/smack/UserRoster.java
private void fireRosterChangedEvent(Collection<String> addedEntries,
            Collection<String> updatedEntries, Collection<String> deletedEntries) {
        for (RosterListener listener : rosterListeners) {
            if (!addedEntries.isEmpty()) {
                listener.entriesAdded(addedEntries);
            }
            if (!updatedEntries.isEmpty()) {
                listener.entriesUpdated(updatedEntries);
            }
            if (!deletedEntries.isEmpty()) {
                listener.entriesDeleted(deletedEntries);
            }
        }
    }
private void fireRosterChangedEvent(Collection<String> addedEntries,
            Collection<String> updatedEntries, Collection<String> deletedEntries) {
        for (RosterListener listener : rosterListeners) {
            if (!addedEntries.isEmpty()) {
                listener.entriesAdded(addedEntries);
            }
            if (!updatedEntries.isEmpty()) {
                listener.entriesUpdated(updatedEntries);
            }
            if (!deletedEntries.isEmpty()) {
                listener.entriesDeleted(deletedEntries);
            }
        }
    }
Fires roster changed event to roster listeners indicating that the
specified collections of contacts have been added, updated or deleted
from the roster.

@param addedEntries
the collection of address of the added contacts.
@param updatedEntries
the collection of address of the updated contacts.
@param deletedEntries
the collection of address of the deleted contacts.