public static void removeAllUsers(){
  Preferences prefs=getPrefs();
  prefs.remove(USERS);
  prefs.remove(ACTIVE_USER);
  flushPrefs(prefs);
}

public static void removeAllUsers ( ) { Preferences prefs = getPrefs ( ) ; prefs . remove ( USERS ) ; prefs . remove ( ACTIVE_USER ) ; flushPrefs ( prefs ) ; }
clears all persistently stored users . there is no active user after this .
