output?

Returns true if argument is output.

tobj = WIN32OLE_TYPE.new('Microsoft Internet Controls', 'DWebBrowserEvents')
method = WIN32OLE_METHOD.new(tobj, 'NewWindow')
method.params.each do |param|
  puts "#{param.name} #{param.output?}"
end

The result of above script is following:
  URL false
  Flags false
  TargetFrameName false
  PostData false
  Headers false
  Processed true