code: def _post(self, url, data=None, **kwargs):
          
  
          # Remove non-ASCII characters from filenames due to a limitation of the combination of
          # urllib3 (via python-requests) and our server
          # https://github.com/requests/requests/issues/2117
          # Internal Ticket #3090
          if "files" in kwargs and kwargs["files"] is not None:
              acceptable_chars = "0123456789" + "abcdefghijklmnopqrstuvwxyz" + \
                                 "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + " _-.,()[]{}"
              for param_name, fp in kwargs["files"].items():
                  if isinstance(fp, (tuple, list)):
                      filename, fp = fp
                  else:
                      filename = requests.utils.guess_filename(fp) or param_name
  
                  def encode(char):
                      try:
                          if char in acceptable_chars:
                              return char
                      except UnicodeDecodeError:
                          pass
                      return "x{:02x}".format(ord(char))
                  filename = "".join(encode(x) for x in filename)
  
                  kwargs["files"][param_name] = (filename, fp)
  
          for i in itertools.count(1):
              try:
                  return self.session.post(url, data=data, timeout=self.timeout, **kwargs)
              except requests.exceptions.Timeout as e:
                  # exhausted all retries
                  if i >= self.retries:
                      raise ConnectionError(e)
              except requests.exceptions.RequestException as e:
                  raise ConnectionError(e)
  
              # exponential backoff
              max_backoff = 4 ** i / 10   # .4, 1.6, 6.4, 25.6, ...
              time.sleep(random.uniform(0, max_backoff))
docs: Wrapper around requests.post which
  
              (a) always inserts a timeout
              (b) converts errors to ConnectionError
              (c) re-tries a few times
              (d) converts file names to ASCII