void startRowGroup(String type) throws SAXException {
        if (needSuppressStart()) {
            return;
        }
        switch (state) {
            case IN_IMPLICIT_ROW_GROUP:
                current.end();
            // fall through
            case IN_TABLE_AT_START:
            case IN_TABLE_COLS_SEEN:
            case IN_TABLE_AT_POTENTIAL_ROW_GROUP_START:
                current = new RowGroup(this, type);
                state = State.IN_ROW_GROUP;
                break;
            default:
                suppressedStarts = 1;
                break;
        }
    }
Constructor.
@param owner reference back to the checker
src/nu/validator/checker/table/Table.java