code: def urls(self, key, value):
      
      description = force_single_element(value.get('y'))
      url = value.get('u')
  
      linkedin_match = LINKEDIN_URL.match(url)
      twitter_match = TWITTER_URL.match(url)
      wikipedia_match = WIKIPEDIA_URL.match(url)
      if linkedin_match:
          self.setdefault('ids', []).append(
              {
                  'schema': 'LINKEDIN',
                  'value': unquote_url(linkedin_match.group('page')),
              }
          )
      elif twitter_match:
          self.setdefault('ids', []).append(
              {
                  'schema': 'TWITTER',
                  'value': twitter_match.group('handle'),
              }
          )
      elif wikipedia_match:
          lang = wikipedia_match.group('lang')
          page = unquote_url(wikipedia_match.group('page'))
          if lang != 'en':
              page = ':'.join([lang, page])
          self.setdefault('ids', []).append(
              {
                  'schema': 'WIKIPEDIA',
                  'value': page,
              }
          )
      else:
          return {
              'description': description,
              'value': url,
          }
docs: Populate the ``url`` key.
  
      Also populates the ``ids`` key through side effects.