public Optimizer getOptimizer(Class<?> clazz) {
        if (clazz == gbdtOptimizer.getClass())
            return gbdtOptimizer;
        if (clazz == gbdtForestOptimizer.getClass())
            return gbdtForestOptimizer;
        if (clazz == tensorOptimizer.getClass())
            return tensorOptimizer;
        return null;
    }
Gets an optimizer instance used by this by class name, or null if the optimizer is not known
searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/ExpressionOptimizer.java