AttributeError: 'Legend' object has no attribute 'legendHandles'

[JasonGross]

MultiDimensionalFeatures/intervention/appendix_plots.ipynb

Line 111 in 5779a02

" for i in range(len(legend.legendHandles)):\n",

gives
AttributeError: 'Legend' object has no attribute 'legendHandles'

My version of matplotlib is

% pip list | grep matplot
matplotlib                 3.9.1
matplotlib-inline          0.1.7

https://github.com/matplotlib/matplotlib/blob/42b88d01fdd93846d925b1097167d36ea31c7733/doc/api/prev_api_changes/api_changes_3.9.0/removals.rst?plain=1#L147
claims it was removed in 3.9.0 and legend_handles should be used instead