# File lib/capybara/driver/celerity_driver.rb, line 35
    def unselect(option)
      unless node.multiple?
        raise Capybara::UnselectNotAllowed, "Cannot unselect option '#{option}' from single select box."
      end

      # FIXME: couldn't find a clean way to unselect, so clear and reselect
      selected_options = node.selected_options
      if unselect_option  = selected_options.detect { |value| value == option } ||
                            selected_options.detect { |value| value.index(option) }
        node.clear
        (selected_options - [unselect_option]).each { |value| node.select_value(value) }
      else
        options = all(:xpath, "//option").map { |o| "'#{o.text}'" }.join(', ')
        raise Capybara::OptionNotFound, "No such option '#{option}' in this select box. Available options: #{options}"
      end
    end