docs: def encode_multipart_formdata(fields):
      """
      fields is a sequence of (name, value) elements for regular form fields.
      files is a sequence of (name, filename, value) elements for data to be
      uploaded as files.
      Return (content_type, body) ready for httplib.HTTP instance
      """
      BOUNDARY = '----------ThIs_Is_tHe_bouNdaRY_$'
      CRLF = '\r\n'.encode('utf-8')
      L = []
      for (key, value) in fields:
          if not isinstance(value, types.InputFile):
              _append_bytes(L, '--' + BOUNDARY)
              _append_bytes(L, 'Content-Disposition: form-data; name="%s"' % key)
              _append_bytes(L, '')
              _append_bytes(L, value)
          else:
              _append_bytes(L, '--' + BOUNDARY)
              _append_bytes(L, 'Content-Disposition: form-data; name="%s"; filename="%s"' % (key, value.name))
              _append_bytes(L, 'Content-Type: %s' % value.content_type)
              _append_bytes(L, '')
              _append_bytes(L, value.content)
      _append_bytes(L, '--' + BOUNDARY + '--')
      _append_bytes(L, '')
      body = CRLF.join(L)
      content_type = 'multipart/form-data; boundary=%s' % BOUNDARY
      return content_type, body