private void makeDocumentIdTransformIfAppropriate(SummaryField summaryField)
    {
        if (summaryField.getName().equals(SummaryClass.DOCUMENT_ID_FIELD)) {
            summaryField.setTransform(SummaryTransform.DOCUMENT_ID);
        }
    }
Adds the corresponding summary transform for all "documentid" summary fields.
For summary fields without an existing transform:
- Adds the attribute transforms  where the source field has an attribute vector.
- Adds the attribute combiner transform where the source field is a struct field where all subfields have attribute
  vector.
- Add the copy transform where the source field is a struct or map field with a different name.

@author geirst
config-model/src/main/java/com/yahoo/schema/processing/AdjustSummaryTransforms.java