entity_values = []
        entity_key = ""
        for row in entity_keys:
            entity_key = row.join_keys[0]
            entity_values.append(
                getattr(row.entity_values[0], row.entity_values[0].WhichOneof("val"))  # type: ignore[arg-type]
            )

    entities = {}
    for row in entity_keys:
        if len(row.join_keys) != len(row.entity_values):
            raise ValueError(
                "EntityKeyProto has mismatched join_keys and entity_values lengths."
            )

        for join_key, entity_value in zip(row.join_keys, row.entity_values):
            value_attr = entity_value.WhichOneof("val")
            if value_attr is None:
                entities[join_key].append(None)
            else:
                entities[join_key].append(getattr(entity_value, value_attr))

    return {
        "features": api_requested_features,
        "entities": dict(entities),
    }