Problem with Reindexing in the Cadence Classifier

[RichardFreedman]

Some, but not all pieces throw and error in the Cadence Classifier. I find this in VS Code and also in Jupyter NBs.

CRIM_Model_0001.mei, for instance, is a problem. CRIM_Model_0008 or CRIM_Model_0025 are not.

piece_id = 'CRIM_Model_0001'
ns = 'https://crimproject.org/mei/'
suff = '.mei'
piece = import_m21_score(ns + piece_id + suff)
cads = piece.classifyCadences()
cads

The error is: ValueError: cannot reindex from a duplicate axis

And it references Line 1140 of the main_objs.py fle