@Override
    public void process(boolean validate, boolean documentsOnly) {
        DocumentSummary defaultSummary = schema.getSummariesInThis().get("default");
        if (defaultSummary == null) {
            defaultSummary = new DocumentSummary("default", schema);
            defaultSummary.setFromDisk(true); // As we add documentid to this
            schema.addSummary(defaultSummary);
        }

        for (SDField field : schema.allConcreteFields()) {
            collectSummaries(field, schema, validate);
        }
        for (DocumentSummary documentSummary : schema.getSummaries().values()) {
            documentSummary.purgeImplicits();
        }
    }
Makes implicitly defined summaries into explicit summaries

@author bratseth
config-model/src/main/java/com/yahoo/schema/processing/ImplicitSummaries.java