@Override
        protected boolean shouldConvert(Expression exp) {
            if (exp instanceof ZCurveExpression) {
                seenZcurve = true;
                return true;
            }
            if (seenZcurve && exp instanceof AttributeExpression attrExp) {
                return attrExp.getFieldName().endsWith(zSuffix);
            }
            return false;
        }
An indexing language script derived from a schema. An indexing script contains a set of indexing
statements, organized in a composite structure of indexing code snippets.

@author bratseth
config-model/src/main/java/com/yahoo/schema/derived/IndexingScript.java