Configuring Animal speech with a single variable

animal_sounds.rb

class Animal
  @@config = {}
  
  def self.config
    @@config
  end
  
  def speak
    if self.class.config[:verbose] == true
      verbose_speech
    else
      brief_speech
    end
  end
  
  def verbose_speech
    ''
  end
  
  def brief_speech
    ''
  end
end

class Dog < Animal
  def verbose_speech
    "WOOF! WOOF WOOF WOOF!"
  end
  
  def brief_speech
    "WOOF!"
  end
end

Dog.new.speak # => "WOOF!"
Animal.config[:verbose] = true
Dog.new.speak # => "WOOF! WOOF WOOF WOOF!"