define_callbacks

# File activerecord/lib/active_record/associations/builder/belongs_to.rb, line 20
    def self.define_callbacks(model, reflection)
      super
      add_counter_cache_callbacks(model, reflection) if reflection.options[:counter_cache]
      add_touch_callbacks(model, reflection)         if reflection.options[:touch]
      add_default_callbacks(model, reflection)       if reflection.options[:default]
    end