class ObjectKeysFunction {

    public static void register(Functions.Builder module) {<FILL_FUNCTION_BODY>}
}

        module.add(
            Signature.scalar(
                "object_keys",
                DataTypes.UNTYPED_OBJECT.getTypeSignature(),
                DataTypes.STRING_ARRAY.getTypeSignature()
            ).withFeature(Scalar.Feature.NULLABLE),
            (signature, boundSignature) ->
            new UnaryScalar<>(
                signature,
                boundSignature,
                DataTypes.UNTYPED_OBJECT,
                obj -> new ArrayList<>(obj.keySet())
            )
        );
    
<no_super_class>