def each
      instance_variables.each do |ivar|
        name = ivar.to_s.sub(/^@/, '')
        yield(name.to_sym, send(name))
      end
    end
def each
      instance_variables.each do |ivar|
        name = ivar.to_s.sub(/^@/, '')
        yield(name.to_sym, send(name))
      end
    end
Yields over every option key and value
 @yield [key, value] every option key and value
 @yieldparam [Symbol] key the option key
 @yieldparam [Object] value the option value
 @return [void]