Updated example

examples/tune_vgg16_cifar10.py

@@ -42,10 +42,11 @@ baseline, _ = app.measure_qos_cost({}, False)
 # Get a tuner object and start tuning!
 tuner = app.get_tuner()
 tuner.tune(
-    max_iter=500,  # TODO: In practice, use at least 5000, or 10000
-    qos_tuner_threshold=2.1,  # QoS threshold to guide tuner into
+    max_iter=1000,  # TODO: In practice, use at least 5000, or 10000
+    qos_tuner_threshold=2.0,  # QoS threshold to guide tuner into
     qos_keep_threshold=3.0,  # QoS threshold for which we actually keep the configurations
     is_threshold_relative=True,  # Thresholds are relative to baseline -- baseline_acc - 2.1
+    take_best_n=20,  # Take the best 20 configs (not just the "strictly" best ones)
     cost_model="cost_linear",  # Use linear performance predictor
     qos_model="qos_p1",  # Use P1 QoS predictor
 )