```
ROW a="b c d"
| DISSECT a "%{b} %{} %{d}"
```
returns

```
       a       |       b       |               |       d       
---------------+---------------+---------------+---------------
b c d          |b              |null           |d 
```

it should ignore the empty pattern instead, and only return `a, b, d`
x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/parser/StatementParserTests.java
LogicalPlan plan = statement("from text | where true | sort a+b asc nulls first, x desc nulls last | sort y asc | sort z desc");
        assertThat(plan, instanceOf(OrderBy.class));
        OrderBy orderBy = (OrderBy) plan;
        assertThat(orderBy.order().size(), equalTo(1));
        Order order = orderBy.order().get(0);
        assertThat(order.direction(), equalTo(Order.OrderDirection.DESC));
        assertThat(order.nullsPosition(), equalTo(Order.NullsPosition.FIRST));
        assertThat(order.child(), instanceOf(UnresolvedAttribute.class));
        assertThat(((UnresolvedAttribute) order.child()).name(), equalTo("z"));
        assertThat(orderBy.children().size(), equalTo(1));
        assertThat(orderBy.children().get(0), instanceOf(OrderBy.class));
        orderBy = (OrderBy) orderBy.children().get(0);
        assertThat(orderBy.order().size(), equalTo(1));
        order = orderBy.order().get(0);
        assertThat(order.direction(), equalTo(Order.OrderDirection.ASC));
        assertThat(order.nullsPosition(), equalTo(Order.NullsPosition.LAST));
        assertThat(order.child(), instanceOf(UnresolvedAttribute.class));
        assertThat(((UnresolvedAttribute) order.child()).name(), equalTo("y"));
        assertThat(orderBy.children().size(), equalTo(1));
        assertThat(orderBy.children().get(0), instanceOf(OrderBy.class));
        orderBy = (OrderBy) orderBy.children().get(0);
        assertThat(orderBy.order().size(), equalTo(2));
        order = orderBy.order().get(0);
        assertThat(order.direction(), equalTo(Order.OrderDirection.ASC));
        assertThat(order.nullsPosition(), equalTo(Order.NullsPosition.FIRST));
        assertThat(order.child(), instanceOf(Add.class));
        Add add = (Add) order.child();
        assertThat(add.left(), instanceOf(UnresolvedAttribute.class));
        assertThat(((UnresolvedAttribute) add.left()).name(), equalTo("a"));
        assertThat(add.right(), instanceOf(UnresolvedAttribute.class));