hidden_proxy.rb

class HiddenProxy < BasicObject
  def initialize(proxy)
    @proxy = proxy
  end

  def method_missing(m, *a, &b)
    if m.to_s =~ /^to_(.+)!$/
      @proxy = @proxy.send("to_#{$1}", *a, &b)
    else
      ::HiddenProxy.new(@proxy.send(m, *a, &b))
    end
  end
end