docs: def multipart(body, content_length=0, **header_params):
      """Converts multipart form data into native Python objects"""
      header_params.setdefault('CONTENT-LENGTH', content_length)
      if header_params and 'boundary' in header_params:
          if type(header_params['boundary']) is str:
              header_params['boundary'] = header_params['boundary'].encode()
  
      form = parse_multipart((body.stream if hasattr(body, 'stream') else body), header_params)
      for key, value in form.items():
          if type(value) is list and len(value) is 1:
              form[key] = value[0]
      return form