void startColGroup(int span) {
        if (needSuppressStart()) {
            return;
        }
        switch (state) {
            case IN_TABLE_AT_START:
                hardWidth = true;
                columnCount = 0;
            // fall through
            case IN_TABLE_COLS_SEEN:
                pendingColGroupSpan = span;
                state = State.IN_COLGROUP;
                break;
            default:
                suppressedStarts = 1;
                break;
        }
    }
Constructor.
@param owner reference back to the checker
src/nu/validator/checker/table/Table.java