<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def search_results_last_url(html, xpath, label):
 """ Get the URL of the 'last' button in a search results listing. """

    for container in html.findall(xpath):
        if container.text_content().strip() == label:
            return container.find('.//a').get('href')