class Object
  def self.query( classes=nil, &blk )
    objs = []
    if mod
      ObjectSpace.each_object(mod) do |o|
        objs << o if blk.call(o)
      end
    else
      ObjectSpace.each_object do |o|
        objs << o if blk.call(o)
      end
    end
    return objs
  end
end