Outputting '=== as string, not formula

[tibo....@gmail.com]

Hi there,

How can I output a series of '=' without it being interpreted as a formula? I tried prepending a single quote but that shows in the cell also.

wb = xlsx_package.workbook
wb.add_worksheet(name: "formatted text") do |sheet|
lines = [
%Q{-----------------},
%Q{ blah },
%Q{'============},
]
lines.each do |line|
sheet.add_row [line], types: [:string]
end
end

Thanks for the help!