import java.util.IdentityHashMap;
import java.util.Map;

public class Test {
    public static void main(String[] args)  {
        IdentityHashMap<String, String> mutMap = new IdentityHashMap<>();
        mutMap.put("test", "initial");
        Map.Entry<String, String> arrayEntry =
                (Map.Entry<String, String>) mutMap.entrySet().toArray()[0];
        boolean flag = mutMap.entrySet().contains(arrayEntry);
        System.out.println(flag);
        System.out.println(arrayEntry);
        arrayEntry.setValue("modified");
        System.out.println("MapEntry: "+arrayEntry);
        System.out.println("IdentityHashMap: "+mutMap);
        mutMap.put("test", "modified2");
        System.out.println("MapEntry: "+arrayEntry);
        System.out.println("IdentityHashMap: "+mutMap);
    }
}