logging in default method of interface

package com.codeuniverse.jackpotalert.candidates.filtering;

import java.util.LinkedHashSet;
import java.util.Set;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.codeuniverse.jackpotalert.domain.Draw5x36;

// for logging in default method of CandidateFilter interface
final class CandidateFilterLogHolder {
    static final Logger logger = LoggerFactory.getLogger(CandidateFilter.class);
}

/**
 * to make array of pluggable methods to pre-screen candidate-draws-to-play
 *
 */
public interface CandidateFilter {


    boolean isBadCandidate(Draw5x36 candidateDraw);

    /**
     * что это за фильтр и что он делает
     *
     * @return
     */
    String getFilterDescription();



     public default Set<Draw5x36> filterCandidates(Set<Draw5x36> candidates) {
        Set<Draw5x36> candidatesCopy = new LinkedHashSet<>(candidates);
        int removeCounterForLogging = 0;
        for (Draw5x36 draw : candidates) {
            if (isBadCandidate(draw)) {
                candidatesCopy.remove(draw);
                removeCounterForLogging++;
            } else {
                continue;
            }
        }
        CandidateFilterLogHolder.logger.debug("CandidatePreScreener.filterCandidates() by " + getFilterDescription() +  " got: " + candidates.size()
                + ", removed: " + removeCounterForLogging + " and returned: " + candidatesCopy.size()
                + " candidate-draws");

        return candidatesCopy;
    }


}