Index.tolist returns empty list for MultiIndex
In [18]: idx
Out[18]: 
MultiIndex
[(0.12609189981717644, 1.103678121647419)
 (0.34279706720294867, -0.7021022763765951)
 (1.4611933034915323, -0.9892166873678242)
 (-1.8708717491582252, 1.0296013286162102)

In [19]: len(idx.tolist())
Out[19]: 0
