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