private void checkSummaryTransform(ChangeMessageBuilder builder) {
        for (SummaryField nextSummaryField : nextField.getSummaryFields().values()) {
            String fieldName = nextSummaryField.getName();
            SummaryField currentSummaryField = currentField.getSummaryField(fieldName);
            if (currentSummaryField != null) {
                SummaryTransform currentTransform = currentSummaryField.getTransform();
                SummaryTransform nextTransform = nextSummaryField.getTransform();
                if (currentSummaryField.getTransform() != nextSummaryField.getTransform()) {
                    builder.addChange("summary field '" + fieldName + "' transform",
                            currentTransform.getName(), nextTransform.getName());
                }
            }
        }
    }
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