code: def check_content_size(url, headers, max_content_bytes):
      
      if not max_content_bytes:
          return
      if 'content-length' in headers:
          size = int(headers['content-length'])
          if size > max_content_bytes:
              msg = 'URL content of %s with %d bytes exceeds %d bytes.' % (url, size, max_content_bytes)
              raise IOError(msg)
docs: Check that content length in URL response headers do not exceed the
      given maximum bytes.