@Override
    public List<ImmutableSDField> allFieldsList() {
        List<ImmutableSDField> all = new ArrayList<>(extraFieldList());
        for (Field field : documentType.fieldSet()) {
            all.add((ImmutableSDField) field);
        }
        if (importedFields.isPresent()) {
            for (ImportedField imported : importedFields.get().fields().values()) {
                all.add(imported.asImmutableSDField());
            }
        }
        return all;
    }
Returns a map of the fields defined explicitly in this schema
(that is, not including inherited fields).
config-model/src/main/java/com/yahoo/schema/Schema.java