# File lib/active_support/callbacks.rb, line 521 def reset_callbacks(symbol) callbacks = send("_#{symbol}_callbacks") ActiveSupport::DescendantsTracker.descendants(self).each do |target| chain = target.send("_#{symbol}_callbacks") callbacks.each { |c| chain.delete(c) } target.__define_runner(symbol) end callbacks.clear __define_runner(symbol) end