private static List <Tuple <int, TimeSpan, int> > _MeasureTime(int conc,
                                                                       string engine, IDataScorerTransform scorer, ITransformer transformer,
                                                                       int N, int ncall, bool cacheScikit)
        {
            var args = new TextLoader.Arguments()
            {
                Separator = "tab",
                HasHeader = true,
                Column    = new[]
                {
                    new TextLoader.Column("Label", DataKind.BL, 0),
                    new TextLoader.Column("SentimentText", DataKind.Text, 1)
                }
            };

            var testFilename = FileHelper.GetTestFile("wikipedia-detox-250-line-test.tsv");
            var times        = new List <Tuple <int, TimeSpan, int> >();

            using (var env = EnvHelper.NewTestEnvironment(seed: 1, conc: conc))
            {
                // Take a couple examples out of the test data and run predictions on top.
                var       testLoader = TextLoader.ReadFile(env, args, new MultiFileSource(testFilename));
                IDataView cache;
                if (cacheScikit)
                {
                    cache = new ExtendedCacheTransform(env, new ExtendedCacheTransform.Arguments(), testLoader);
                }
                else
                {
                    cache = new CacheDataView(env, testLoader, new[] { 0, 1 });
                }
                var testData = cache.AsEnumerable <SentimentData>(env, false);

                if (engine == "mlnet")
                {
                    Console.WriteLine("engine={0} N={1} ncall={2} cacheScikit={3}", engine, N, ncall, cacheScikit);
                    var fct = transformer.MakePredictionFunction <SentimentData, SentimentPrediction>(env);
                    var sw  = new Stopwatch();
                    for (int call = 1; call <= ncall; ++call)
                    {
                        sw.Reset();
                        sw.Start();
                        for (int i = 0; i < N; ++i)
                        {
                            foreach (var input in testData)
                            {
                                fct.Predict(input);
                            }
                        }
                        sw.Stop();
                        times.Add(new Tuple <int, TimeSpan, int>(N, sw.Elapsed, call));
                    }
                }
                else if (engine == "scikit")
                {
                    Console.WriteLine("engine={0} N={1} ncall={2} cacheScikit={3}", engine, N, ncall, cacheScikit);
                    var model  = new ValueMapperPredictionEngine <SentimentData>(env, scorer, conc: conc);
                    var output = new ValueMapperPredictionEngine <SentimentData> .PredictionTypeForBinaryClassification();

                    var sw = new Stopwatch();
                    for (int call = 1; call <= ncall; ++call)
                    {
                        sw.Reset();
                        sw.Start();
                        for (int i = 0; i < N; ++i)
                        {
                            foreach (var input in testData)
                            {
                                model.Predict(input, ref output);
                            }
                        }
                        sw.Stop();
                        times.Add(new Tuple <int, TimeSpan, int>(N, sw.Elapsed, call));
                    }
                }
                else
                {
                    throw new NotImplementedException($"Unknown engine '{engine}'.");
                }
            }
            return(times);
        }
        private List <Tuple <int, TimeSpan, int, float[]> > _MeasureTime(int conc,
                                                                         string strategy, string engine, IDataScorerTransform scorer, ITransformer trscorer, int ncall)
        {
            var testFilename = FileHelper.GetTestFile("wikipedia-detox-250-line-test.tsv");
            var times        = new List <Tuple <int, TimeSpan, int, float[]> >();

            /*using (*/
            var env = EnvHelper.NewTestEnvironment(seed: 1, conc: conc);

            {
                if (engine == "mlnet")
                {
                    var args = new TextLoader.Options()
                    {
                        Separators = new[] { '\t' },
                        HasHeader  = true,
                        Columns    = new[] {
                            new TextLoader.Column("Label", DataKind.Boolean, 0),
                            new TextLoader.Column("SentimentText", DataKind.String, 1)
                        }
                    };

                    // Take a couple examples out of the test data and run predictions on top.
                    var       testLoader = new TextLoader(env, args).Load(new MultiFileSource(testFilename));
                    IDataView cache;
                    if (strategy.Contains("extcache"))
                    {
                        cache = new ExtendedCacheTransform(env, new ExtendedCacheTransform.Arguments(), testLoader);
                    }
                    else
                    {
                        cache = new CacheDataView(env, testLoader, new[] { 0, 1 });
                    }
                    //var testData = cache.AsEnumerable<SentimentDataBoolFloat>(env, false);
                    //var testDataArray = cache.AsEnumerable<SentimentDataBoolFloat>(env, false).ToArray();
                    int N = 1;

                    var model = ComponentCreation.CreatePredictionEngine <SentimentDataBoolFloat, SentimentPrediction>(env, trscorer);
                    var sw    = new Stopwatch();
                    for (int call = 1; call <= ncall; ++call)
                    {
                        sw.Reset();
                        var pred = new List <float>();
                        sw.Start();
                        for (int i = 0; i < N; ++i)
                        {
                            if (strategy.Contains("array"))
                            {
                                /*
                                 * foreach (var input in testDataArray)
                                 *  pred.Add(model.Predict(input).Score);
                                 */
                            }
                            else
                            {
                                /*
                                 * foreach (var input in testData)
                                 *  pred.Add(model.Predict(input).Score);
                                 */
                            }
                        }
                        sw.Stop();
                        times.Add(new Tuple <int, TimeSpan, int, float[]>(N, sw.Elapsed, call, pred.ToArray()));
                    }
                }
                else if (engine == "scikit")
                {
                    var args = new TextLoader.Options()
                    {
                        Separators = new[] { '\t' },
                        HasHeader  = true,
                        Columns    = new[] {
                            new TextLoader.Column("Label", DataKind.Boolean, 0),
                            new TextLoader.Column("SentimentText", DataKind.String, 1)
                        }
                    };

                    // Take a couple examples out of the test data and run predictions on top.
                    var       testLoader = new TextLoader(env, args).Load(new MultiFileSource(testFilename));
                    IDataView cache;
                    if (strategy.Contains("extcache"))
                    {
                        cache = new ExtendedCacheTransform(env, new ExtendedCacheTransform.Arguments(), testLoader);
                    }
                    else
                    {
                        cache = new CacheDataView(env, testLoader, new[] { 0, 1 });
                    }
                    //var testData = cache.AsEnumerable<SentimentDataBool>(env, false);
                    //var testDataArray = cache.AsEnumerable<SentimentDataBool>(env, false).ToArray();
                    int N = 1;

                    string allSchema = SchemaHelper.ToString(scorer.Schema);
                    Assert.IsTrue(allSchema.Contains("PredictedLabel:Bool:4; Score:R4:5; Probability:R4:6"));
                    var model  = new ValueMapperPredictionEngine <SentimentDataBool>(env, scorer);
                    var output = new ValueMapperPredictionEngine <SentimentDataBool> .PredictionTypeForBinaryClassification();

                    var sw = new Stopwatch();
                    for (int call = 1; call <= ncall; ++call)
                    {
                        var pred = new List <float>();
                        sw.Reset();
                        sw.Start();
                        for (int i = 0; i < N; ++i)
                        {
                            if (strategy.Contains("array"))
                            {
                                /*
                                 * foreach (var input in testDataArray)
                                 * {
                                 *  model.Predict(input, ref output);
                                 *  pred.Add(output.Score);
                                 * }
                                 */
                            }
                            else
                            {
                                /*
                                 * foreach (var input in testData)
                                 * {
                                 *  model.Predict(input, ref output);
                                 *  pred.Add(output.Score);
                                 * }
                                 */
                            }
                        }
                        sw.Stop();
                        times.Add(new Tuple <int, TimeSpan, int, float[]>(N, sw.Elapsed, call, pred.ToArray()));
                    }
                }
                else
                {
                    throw new NotImplementedException($"Unknown engine '{engine}'.");
                }
            }
            return(times);
        }