# File lib/cgikit/session_store.rb, line 140
  def sweep_sessions
    before = @caches.size
    @caches.delete_if do |id, session|
      session.timeout?
    end
    deleted = before - @caches.size
    failed = 0
    info("deleted = #{deleted}, failed = #{failed}", true)
    [deleted, failed]
  end