ruby-on-rails - Ruby spreadsheet hiding a column

Question

I am having problems with hiding one of my column in the spreadsheet. I use spreadsheet gem(spreadsheet (0.6.5.9, 0.6.5.5))

i made the entire workbook and trying to hide the 7th column in all the sheets.

workbook.worksheets.each do |sheet|
  sheet.column(7).hidden = true
end

this is not doing it.

Let me know if anybody got it to work

Thanks Ramya