Given this Ruby code using a hook pattern:

Given this Ruby code using a hook pattern:

class Framework
  def self.before_save(&block)
    @before_save_hook = block
  end

  def save
    self.class.instance_variable_get(:@before_save_hook)&.call
    puts 'Saving data'
  end
end

class User < Framework
  before_save { puts 'Validate user' }
end

User.new.save

What is the output when User.new.save is called?