def _concat_same_dtype(self, to_concat, name):
if not len({i.closed for i in to_concat if len(i)}) == <NUM_LIT:1>:<EOL><INDENT>msg = ('<STR_LIT>'<EOL>'<STR_LIT>')<EOL>raise ValueError(msg)<EOL><DEDENT>return super()._concat_same_dtype(to_concat, name)<EOL>
assert that we all have the same .closed
we allow a 0-len index here as well