```
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
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.instanceOf;
import static org.hamcrest.Matchers.is;
public class StatementParserTests extends ESTestCase {
    private static String FROM = "from test";
    EsqlParser parser = new EsqlParser();
    public void testRowCommand() {
        assertEquals(
            new Row(EMPTY, List.of(new Alias(EMPTY, "a", integer(1)), new Alias(EMPTY, "b", integer(2)))),
            statement("row a = 1, b = 2")
        );
    }
    public void testRowCommandImplicitFieldName() {
        assertEquals(
            new Row(
                EMPTY,
                List.of(new Alias(EMPTY, "1", integer(1)), new Alias(EMPTY, "2", integer(2)), new Alias(EMPTY, "c", integer(3)))
            ),
            statement("row 1, 2, c = 3")
        );
    }
    public void testRowCommandLong() {
        assertEquals(new Row(EMPTY, List.of(new Alias(EMPTY, "c", literalLong(2147483648L)))), statement("row c = 2147483648"));
    }
    public void testRowCommandHugeInt() {
        assertEquals(
            new Row(EMPTY, List.of(new Alias(EMPTY, "c", literalUnsignedLong("9223372036854775808")))),
            statement("row c = 9223372036854775808")
        );
        assertEquals(