row->table = ovsdb_idl_table_from_class(txn->idl, class);
row->new = xmalloc(class->n_columns * sizeof *row->new);
row->written = bitmap_allocate(class->n_columns);
row->table = ovsdb_idl_table_from_class(txn->idl, class);
row->new = xmalloc(class->n_columns * sizeof *row->new);
row->written = bitmap_allocate(class->n_columns);