def [](k)
      if RESERVED_FIELDS.include? k.to_sym
        super
      else
        r = attributes.find {|a| a.key.to_s == k.to_s }.value
      end
    end
def [](k)
      if RESERVED_FIELDS.include? k.to_sym
        super
      else
        r = attributes.find {|a| a.key.to_s == k.to_s }.value
      end
    end
Look up attributes