code: def _is_potential_multi_index(columns):
      
      return (len(columns) and not isinstance(columns, MultiIndex) and
              all(isinstance(c, tuple) for c in columns))
docs: 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