@Deprecated(forRemoval = true)
    @SuppressWarnings("removal")
    public static DocumentSerializer create6(GrowableByteBuffer buf) {
        return new VespaDocumentSerializer6(buf);
    }
Creates a serializer for the 6.x document format.
This format is an extension of the 4.2 format.
Deprecated, use createHead instead.
document/src/main/java/com/yahoo/document/serialization/DocumentSerializerFactory.java