public OptimizationReport optimize(RankingExpression expression, ContextIndex contextIndex) {
        OptimizationReport report = new OptimizationReport();
        // Note: Order of optimizations matter
        gbdtOptimizer.optimize(expression, contextIndex, report);
        gbdtForestOptimizer.optimize(expression, contextIndex, report);
        tensorOptimizer.optimize(expression, contextIndex, report);
        return report;
    }
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