Not sure why this is failing the removeFirstNamesDuplicate requirement

The removeFirstNamesDuplicate requirement should have a better explanation of why the requirement is not met. Please someone explain what I am doing wrong

public static void removeFirstNameDuplicates(Map<String, String> map) {
    HashMap<String, String> cloneMap = new HashMap<String, String>(map);
    for (Map.Entry<String, String> kv : cloneMap.entrySet()) {
            removeItemFromMapByValue(map, kv.getValue());
    }
    for (Map.Entry<String, String> kv : cloneMap.entrySet()) {
        if (!map.containsValue(kv.getValue())) {
            map.put(kv.getKey(), kv.getValue());
        }
    }
}