```python In [1]: import pandas as pd In [2]: pd.MultiIndex.from_tuples([('a',), ('b',)]) Out[2]: Index(['a', 'b'], dtype='object') ``` This should return a `MultiIndex` I think, like ```python Out[5]: MultiIndex(levels=[['a', 'b']], labels=[[0, 1]]) ``` Well, `pd.MultiIndex([['a', 'b']], [[0, 1]])` returns the same thing as `from_tuples` (an index) so maybe this is intentional. Trying to figure out if this is intentional or not (this came up in my categorical dtype refactor).