respond_to?

# File activerecord/lib/active_record/base.rb, line 1590
      def respond_to?(method, include_priv = false)
        if @attributes.nil?
          return super 
        elsif attr_name = self.class.column_methods_hash[method.to_sym]
          return true if @attributes.include?(attr_name) || attr_name == self.class.primary_key
          return false if self.class.read_methods.include?(attr_name)
        elsif @attributes.include?(method_name = method.to_s)
          return true
        elsif md = /(=|\?|_before_type_cast)$/.match(method_name)
          return true if @attributes.include?(md.pre_match)
        end
        # super must be called at the end of the method, because the inherited respond_to?
        # would return true for generated readers, even if the attribute wasn't present
        super
      end