@Override
    public ExpressionNode transform(ExpressionNode node, RankProfileTransformContext context) {
        if (node instanceof ReferenceNode)
            return transformFeatureNode((ReferenceNode)node, context);
        if (node instanceof CompositeNode)
            return transformChildren((CompositeNode)node, context);
        return node;
    }
Inlines functions in ranking expressions

@author bratseth
config-model/src/main/java/com/yahoo/schema/expressiontransforms/FunctionInliner.java