ruby – 选择多种选择的所有选项与水豚黄瓜

<select id="id_agents" style="" size="10" multiple="multiple" name="id_agents[]">
<option value="12">adama</option>
<option value="15">artica</option>
<option value="14">localhost</option>
<option value="8">localhost.localdomain</option>
<option value="13">test</option>
</select>

我正在尝试使用黄瓜来选择所有值,但它没有运行.这些是我的尝试：

When /^I select all in "(.*)"/ do |select_id|
    options = all(:xpath, "//select[@id='" + select_id + "']/option").click
    options.each do |option|
        option.click
    end
    #~ find(:xpath, "//select[@id='" + select_id + "']/option").each do |element|
        #~ element.click
    #~ end
    sleep(10)
end

select = page.find('select#select_id')
select.select 'Option 1'
select.select 'Option 2'
select.select 'Option 3'
select.unselect 'Option 1'