class Dungeon < ActiveRecord::Base has_many :traps end class Trap < ActiveRecord::Base belongs_to :dungeon end d = Dungeon.first t = d.traps.first d.level == t.dungeon.level # => true d.level = 10 d.level == t.dungeon.level # => false d.object_id == t.dungeon.object_id #=> false class Dungeon < ActiveRecord::Base has_many :traps, :inverse_of => :dungeon end class Trap < ActiveRecord::Base belongs_
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