def update args
      args.each do |key, value|
        method = "#{key}=".to_sym 
        if self.respond_to? method
          self.send(method, value)
        end
      end
    end
def update args
      args.each do |key, value|
        method = "#{key}=".to_sym 
        if self.respond_to? method
          self.send(method, value)
        end
      end
    end
update multiple attrubutes at once