# File lib/chef/provider/deploy.rb, line 177
      def callback(what, callback_code=nil)
        @collection = Chef::ResourceCollection.new
        case callback_code
        when Proc
          Chef::Log.info "#{@new_resource} running callback #{what}"
          recipe_eval(&callback_code)
        when String
          run_callback_from_file("#{release_path}/#{callback_code}")
        when nil
          run_callback_from_file("#{release_path}/deploy/#{what}.rb")
        end
      end