private void splitConfig(DocumentmanagerConfig config) {
            for (var dataTypeConfig : config.datatype()) {
                int id = dataTypeConfig.id();
                var old = configMap.put(id, dataTypeConfig);
                if (old != null) {
                    throw new IllegalArgumentException
                        ("Multiple configs for id "+id+" first:\n"+old+"\nsecond:\n"+dataTypeConfig);
                }
            }
        }
One-shot configuration; should be called on a newly constructed manager
document/src/main/java/com/yahoo/document/DocumentTypeManagerConfigurer.java