User Story

As an app dev, I have set a column to 0 width by CellOperationUtil.setColumnWidth(myCell, 0); previously.
Later, I want CellOperationUtil can unhide a 0-width column for me when I set a positive column width.

Acceptance Criteria

• When calling CellOperationUtil.setColumnWidth(myCell, 100);, if myCell has a 0 width, it doesn't take effect. App dev needs to call CellOperationUtil.unhide(myCell.toColumnRange());, too
• Although It's reasonable to call unhide() but it's not clear that setting a column width to 0 will hide a column and needs to call unhide() afterward. If keikai hides a column implicitly when setting a column width to 0 then keikai should do the symmetric operation: unhide a column when setting a column width larger than 0.

Details

• Review the specification: when setting 0 width column, the column hidden state is also set to true.