# File lib/after_commit/active_support_callbacks.rb, line 5
      def self.included(base)
        
        base::Callback.class_eval do
          def have_callback?
            true
          end
        end
        
        base::CallbackChain.class_eval do
          def have_callback?
            any? &:have_callback?
          end
        end
        
        base.class_eval do
          def have_callback?(*callbacks)
            self.class.observers.size > 0 or
            self.class.count_observers > 0 or
            callbacks.any? do |callback|
              self.class.send("#{callback}_callback_chain").have_callback?
            end
          end
        end
        
      end