In the example gallery, under area charts, the Cumulative Count Chart isn't displaying
https://altair-viz.github.io/gallery/cumulative_count_chart.html
The field name needs updated from "IMDB_Rating" to "IMDB Rating"
The Binned Heatmap is another example that uses this dataset and needs underscores replaced with spaces to work
https://altair-viz.github.io/gallery/binned_heatmap.html