@Override
 public Role createRole(String name, int persistentID) {
   RoleImpl result = new RoleImpl(persistentID, name, this);
   myRoles.add(result);
   myRoleManager.fireRolesChanged(this);
   return result;
 }
 @Override
 public void deleteRole(Role role) {
   myRoles.remove(role);
   myRoleManager.fireRolesChanged(this);
 }
 @Override
 public void setEnabled(boolean isEnabled) {
   this.isEnabled = isEnabled;
   myRoleManager.fireRolesChanged(this);
 }