// by the time this function is called, the sizer should be already fully
// initialized and hence the number of its columns and rows is known and we
// can check that all indices in m_growableCols/Rows are valid (see also
// by the time this function is called, the sizer should be already fully
// initialized and hence the number of its columns and rows is known and we
// can check that all indices in m_growableCols/Rows are valid (see also