/**
* Deletes the session associated with the given user ID.
*
* @return True if a session with the given ID existed.
*/
private synchronized boolean deleteSessionByUserID(String userID) {
Session session = mSessionsByUserID.remove(userID);
if (session == null) return false;
mSessionsByID.removeKey(session.getID());
return true;
}
/**
* Deletes the session with the given ID.
*
* @return True if a session with the given ID existed.
*/
private synchronized boolean deleteSession(UUID sessionID) {
Session session = mSessionsByID.get(sessionID);
if (session == null) return false;
mSessionsByID.removeKey(sessionID);
mSessionsByUserID.remove(session.getUserID());
return true;
}