486                  showempty=False,  argument
491     if showempty is None:
492         showempty = False
496          ) = _collate(items, groupby, showempty)
549         if not showempty and group not in collated:
576                 showempty=None,  argument
581     if showempty is None:
582         showempty = False
588         collated, groupby, _, _, _ = _collate(items, groupby, showempty)
625                    showempty=None,  argument
633         includeempty=showempty,
634         minimize=None if showempty else not verbose,