A small example for instantiating different kinds of counters

StatExample.java

package de.learnlib.examples;

import java.util.Random;

import de.learnlib.algorithms.lstar.dfa.ClassicLStarDFA;
import de.learnlib.api.algorithm.LearningAlgorithm.DFALearner;
import de.learnlib.api.oracle.EquivalenceOracle.DFAEquivalenceOracle;
import de.learnlib.api.oracle.MembershipOracle.DFAMembershipOracle;
import de.learnlib.filter.cache.dfa.DFACacheOracle;
import de.learnlib.filter.cache.dfa.DFACaches;
import de.learnlib.filter.statistic.oracle.DFACounterOracle;
import de.learnlib.oracle.equivalence.DFARandomWordsEQOracle;
import de.learnlib.oracle.membership.SimulatorOracle.DFASimulatorOracle;
import de.learnlib.util.Experiment.DFAExperiment;
import net.automatalib.automata.fsa.DFA;
import net.automatalib.util.automata.random.RandomAutomata;
import net.automatalib.words.Alphabet;
import net.automatalib.words.impl.Alphabets;

public class StatExample {

    public static void main(String[] args) {
        final Random random = new Random(42);
        final Alphabet<Integer> alphabet = Alphabets.integers(1, 3);
        final DFA<?, Integer> dfa = RandomAutomata.randomDFA(random, 20, alphabet);

        final DFAMembershipOracle<Integer> oracle = new DFASimulatorOracle<>(dfa);

        final DFACounterOracle<Integer> uniqueCounter = new DFACounterOracle<>(oracle, "Unique Queries by Learner");
        final DFACacheOracle<Integer> cache = DFACaches.createCache(alphabet, uniqueCounter);
        final DFACounterOracle<Integer> mqCounter = new DFACounterOracle<>(cache, "Queries by Learner");

        final DFACounterOracle<Integer> eqCounter = new DFACounterOracle<>(oracle, "Queries by EQ oracle");
        final DFAEquivalenceOracle<Integer> eqOracle =
                new DFARandomWordsEQOracle<>(eqCounter, // use mqCounter for shared number of queries
                                             0, 20, 1000, random);

        final DFALearner<Integer> learner = new ClassicLStarDFA<>(alphabet, mqCounter);
        final DFAExperiment<Integer> experiment = new DFAExperiment<>(learner, eqOracle, alphabet);

        experiment.run();

        System.out.println(uniqueCounter.getStatisticalData());
        System.out.println(mqCounter.getStatisticalData());
        System.out.println(eqCounter.getStatisticalData());
    }
}