def _is_potential_multi_index(columns):
return (len(columns) and not isinstance(columns, MultiIndex) and<EOL>all(isinstance(c, tuple) for c in columns))<EOL>
Check whether or not the `columns` parameter
could be converted into a MultiIndex.

Parameters
----------
columns : array-like
    Object which may or may not be convertible into a MultiIndex

Returns
-------
boolean : Whether or not columns could become a MultiIndex