# File lib/capybara/driver/rack_test_driver.rb, line 68
    def unselect(option)
      if node['multiple'] != 'multiple'
        raise Capybara::UnselectNotAllowed, "Cannot unselect option '#{option}' from single select box."
      end

      if option_node = node.xpath(".//option[text()=#{Capybara::XPath.escape(option)}]").first ||
                       node.xpath(".//option[contains(.,#{Capybara::XPath.escape(option)})]").first
        option_node.remove_attribute('selected')
      else
        options = node.xpath(".//option").map { |o| "'#{o.text}'" }.join(', ')
        raise Capybara::OptionNotFound, "No such option '#{option}' in this select box. Available options: #{options}"
      end
    end