_compile_per_key_options

# File activesupport/lib/active_support/callbacks.rb, line 168
      def _compile_per_key_options
        key_options  = _compile_options(@per_key)

        @klass.class_eval "def _one_time_conditions_valid_\#{@callback_id}?\ntrue \#{key_options[0]}\nend\n", __FILE__, __LINE__ + 1
      end