@Override
    public void process(boolean validate, boolean documentsOnly) {
        schema.allImportedFields()
              .forEach(this::setTransform);
    }
Adds the data type and attribute summary transform ({@link SummaryTransform#ATTRIBUTE} to all {@link SummaryField} having an imported
field as source.

@author bjorncs
config-model/src/main/java/com/yahoo/schema/processing/AddDataTypeAndTransformToSummaryOfImportedFields.java