code: def _length(self):
          
          self._build_chunk_headers()
  
          length = 0
  
          if self._data:
              for field in self._data:
                  length += len(self._chunk_headers[field])
                  length += len(self._data[field])
                  length += 2
  
          if self._files:
              for field in self._files:
                  length += len(self._chunk_headers[field])
                  length += self._file_size(field)
                  length += 2
  
          length += len(self.boundary)
          length += 6
  
          return length
docs: Returns total length for this request.
  
          Returns:
              int. Length