def defaults
      @values = Hash[self.class.options.select { |_, c| c.key?(:default) }.map { |n,c| [n, c[:default]] }].merge(@values)
    end
def defaults
      @values = Hash[self.class.options.select { |_, c| c.key?(:default) }.map { |n,c| [n, c[:default]] }].merge(@values)
    end
Get a hash of all options with default values. The list of values is initialized with the result.