```
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/main/java/org/elasticsearch/xpack/esql/parser/LogicalPlanBuilder.java
import org.elasticsearch.xpack.esql.plan.logical.Eval;
import org.elasticsearch.xpack.esql.plan.logical.Explain;
import org.elasticsearch.xpack.esql.plan.logical.Grok;
import org.elasticsearch.xpack.esql.plan.logical.InlineStats;
import org.elasticsearch.xpack.esql.plan.logical.Keep;
import org.elasticsearch.xpack.esql.plan.logical.MvExpand;
import org.elasticsearch.xpack.esql.plan.logical.Rename;
import org.elasticsearch.xpack.esql.plan.logical.Row;
import org.elasticsearch.xpack.esql.plan.logical.show.ShowFunctions;
import org.elasticsearch.xpack.esql.plan.logical.show.ShowInfo;
import org.elasticsearch.xpack.ql.expression.Alias;
import org.elasticsearch.xpack.ql.expression.Attribute;
import org.elasticsearch.xpack.ql.expression.EmptyAttribute;
import org.elasticsearch.xpack.ql.expression.Expression;
import org.elasticsearch.xpack.ql.expression.Expressions;
import org.elasticsearch.xpack.ql.expression.Literal;
import org.elasticsearch.xpack.ql.expression.MetadataAttribute;
import org.elasticsearch.xpack.ql.expression.NamedExpression;
import org.elasticsearch.xpack.ql.expression.Order;
import org.elasticsearch.xpack.ql.expression.ReferenceAttribute;
import org.elasticsearch.xpack.ql.expression.UnresolvedAttribute;
import org.elasticsearch.xpack.ql.expression.UnresolvedStar;
import org.elasticsearch.xpack.ql.parser.ParserUtils;
import org.elasticsearch.xpack.ql.plan.TableIdentifier;
import org.elasticsearch.xpack.ql.plan.logical.Aggregate;
import org.elasticsearch.xpack.ql.plan.logical.Filter;
import org.elasticsearch.xpack.ql.plan.logical.Limit;
import org.elasticsearch.xpack.ql.plan.logical.LogicalPlan;
import org.elasticsearch.xpack.ql.plan.logical.OrderBy;
import org.elasticsearch.xpack.ql.tree.Source;