Things and stuff

ruby-1.9.3-preview1 :015 > t1 = Thing.new
 => #<Thing:0x007fcaf104fa60> 
ruby-1.9.3-preview1 :016 > t2 = Thing.new
 => #<Thing:0x007fcaf2001008> 
ruby-1.9.3-preview1 :017 > t2.cache_some_stuff(:foo, 1)
 => 1 
ruby-1.9.3-preview1 :018 > Thing.instance_variable_get('@cached_stuff')
 => {:foo=>1} 
ruby-1.9.3-preview1 :019 > t1.cached_stuff
 => {:foo=>1} 
ruby-1.9.3-preview1 :020 > t1.cached_stuff[:bar] = 2
 => 2 
ruby-1.9.3-preview1 :021 > t2.cached_stuff[:bar]
 => 2