import com.google.common.collect.testing.Helpers;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;
import java.lang.reflect.Method;
import java.util.Hashtable;
import java.util.Map;
import junit.framework.AssertionFailedError;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link Map#merge}. Can't be invoked directly; please see {@link