private void checkIndexing(ChangeMessageBuilder builder) {
        if (currentField.doesIndexing() != nextField.doesIndexing()) {
            String change = nextField.doesIndexing() ? "add" : "remove";
            builder.addChange(change + " index aspect");
        }
    }
Class used to build a message describing the usual field changes causing changes in the indexing script.
This message should be more descriptive for the end-user than just seeing the changed indexing script.

@author geirst
config-model/src/main/java/com/yahoo/vespa/model/application/validation/change/search/IndexingScriptChangeMessageBuilder.java