private static NewDocumentType newInstance() {
        NewDocumentType vespa = new NewDocumentType(new NewDocumentType.Name(8, "document"));
        vespa.add(DataType.BYTE);
        vespa.add(DataType.INT);
        vespa.add(DataType.LONG);
        vespa.add(DataType.STRING);
        vespa.add(DataType.RAW);
        vespa.add(DataType.TAG);
        vespa.add(DataType.FLOAT);
        vespa.add(DataType.DOUBLE);
        vespa.add(DataType.DOCUMENT);
        vespa.add(PositionDataType.INSTANCE);
        vespa.add(DataType.URI);
        vespa.add(DataType.PREDICATE);
        vespa.add(DataType.BOOL);
        vespa.add(DataType.FLOAT16);
        return vespa;
    }
This class represents the builtin 'document' document type that all other documenttypes inherits.
Remember that changes here must be compatible. Changes to types of fields can not be done here.
This must also match the mirroring class in c++.

@author baldersheim
config-model/src/main/java/com/yahoo/documentmodel/VespaDocumentType.java