class NilDuck
  def name
    'Demo Duck'
  end

  def status
    'sleeping'
  end

  def color
    'gray'
  end

  def migratory?
    true
  end

  def method_missing(name, *args)
    super unless Duck.new.respond_to?(name)
    name.ends_with?('?') ? false : nil
  end
end