docs: def _fetch(self, urls):
          """Perform bulk collection of data and return the content.
  
          Gathering responses is handled by the base class and uses futures to
          speed up the processing. Response data is saved inside a local variable
          to be used later in extraction.
          """
          responses = self._request_bulk(urls)
          for response in responses:
              try:
                  soup = BeautifulSoup(response.content, 'html.parser',
                                       from_encoding="iso-8859-1")
                  text = soup.get_text()
              except Exception:
                  text = response.text
              self.data.append(text) # Opportunistic findings
          return responses