@ Nonnull @ ReturnsMutableCopy public ICommonsList < String > getAllUserGroupIDsWithAssignedUser ( @ Nullable final String sUserID ) { if ( StringHelper . hasNoText ( sUserID ) ) return new CommonsArrayList <> ( ) ; return getAllMapped ( aUserGroup -> aUserGroup . containsUserID ( sUserID ) , aUserGroup -> aUserGroup . getID ( ) ) ; }
Get a collection of all user group IDs to which a certain user is assigned to .