CASE on NULL value

[acquamarin]

This query returns incorrect result:

kuzu> RETURN CASE NULL  WHEN NULL THEN "Null value" ELSE "Not null value" END;
-----------------------------------------------------------
| CASE WHEN EQUALS(,) THEN Null value ELSE Not null value |
-----------------------------------------------------------
| Not null value                                          |
-----------------------------------------------------------
(1 tuple)
(1 column)
Time: 0.24ms (compiling), 0.29ms (executing)

The above query should return "null value" since null is null.