Return list of AccessedFeatures from get_accessed_features (#23983)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23983
While testing I realized that model layers can extract different types of features from the same column. For example, MultifeedFeaturesTransform uses float and ID list features from the "features" column.
get_accessed_features returns a map from column to AccessedFeatures, and AccessedFeatures only has the feature IDs for one feature type. This is incompatible with have multiple types of features per column, one type ends up overwriting another in the map.
To fix this, I've modified get_accessed_features to return a map from column to a list of AccessedFeatures objects.
Reviewed By: itomatik
Differential Revision: D16693845
fbshipit-source-id: 2099aac8dc3920dd61de6b6ad5cf343c864803bc
