Was genuinely surprised Rails `reset_session` doesn't accept a list of exceptions

resets_session_but_its_still_thursday_i_need_these.rb

# If you have any session variables that should survive a logout, add them to
# the except_for array. Usage from a controller:
#
# ResetsSessionButItsStillThursdayINeedThese.new.reset(self,
#   except_for: [:has_logged_in_before])

class ResetsSessionButItsStillThursdayINeedThese
  def reset(receiver, except_for: [])
    backup = except_for.map { |key| [key, receiver.session[key]] }
    receiver.reset_session
    backup.each { |key, value| receiver.session[key] = value }
  end
end