code: def close(self):
          
          if self._tempfile is not None:
              self._tempfile.close()
          if self._file is not None and not self._from_filelike:
              self._file.close()
docs: if the MDF was created with memory='minimum' and new
          channels have been appended, then this must be called just before the
          object is not used anymore to clean-up the temporary file