def get_feature_key_list(feature_keys, domain):
    """Processes node_feature_keys and extracts their feature keys to a list."""
    if isinstance(feature_keys, Dict):
        return [
            (domain, type_name, feature_name)
            for type_name, feature_names in feature_keys.items()
            for feature_name in feature_names
        ]
    elif feature_keys is not None:
        return [(domain, None, feature_name) for feature_name in feature_keys]
    else:
        return []
Processes node_feature_keys and extracts their feature keys to a list.
python/dgl/graphbolt/feature_fetcher.py