code: def read_content(self):
          
          maxbytes = self.aggregate.config["maxfilesizedownload"]
          buf = StringIO()
          for data in self.url_connection.iter_content(chunk_size=self.ReadChunkBytes):
              if buf.tell() + len(data) > maxbytes:
                  raise LinkCheckerError(_("File size too large"))
              buf.write(data)
          return buf.getvalue()
docs: Return data and data size for this URL.
          Can be overridden in subclasses.