presto-main/src/main/java/io/prestosql/sql/planner/iterative/rule/UnwrapCastInComparison.java/UnwrapCastInComparison/falseIfNotNull
class UnwrapCastInComparison:    private static Expression falseIfNotNull(Expression argument)
    {
        return and(new IsNullPredicate(argument), new NullLiteral());
    }