@Override
    public boolean isCellEditable(int rowIndex, int columnIndex) {
	switch (COLUMNS.values()[columnIndex]) {
	    case ID:
		return false;
	    case FIRSTNAME:
	    case LASTNAME:
	    case BIRTH:
	    case EMAIL:
		return true;
	    default:
		throw new IllegalArgumentException("columnIndex");
	}
    }