def convert_missing_indexer(indexer):
if isinstance(indexer, dict):<EOL><INDENT>indexer = indexer['<STR_LIT:key>']<EOL>if isinstance(indexer, bool):<EOL><INDENT>raise KeyError("<STR_LIT>")<EOL><DEDENT>return indexer, True<EOL><DEDENT>return indexer, False<EOL>
reverse convert a missing indexer, which is a dict
return the scalar indexer and a boolean indicating if we converted