V oldValue = forwardDelegate.putIfAbsent(e.getKey(), e.getValue());
      if (oldValue != null) {
        throw conflictException("key", e.getKey() + "=" + oldValue, entryArray[i]);
      }
      K oldKey = backwardDelegate.putIfAbsent(e.getValue(), e.getKey());
      if (oldKey != null) {
        throw conflictException("value", oldKey + "=" + e.getValue(), entryArray[i]);
      }
    }

      K key = entryArray[i].getKey();
      V value = entryArray[i].getValue();
      V oldValue = delegateMap.put(key, value);
      if (oldValue != null) {
        if (throwIfDuplicateKeys) {
          throw conflictException("key", entryArray[i], entryArray[i].getKey() + "=" + oldValue);
        }
        if (duplicates == null) {
          duplicates = new HashMap<>();
        }
        duplicates.put(key, value);
        dupCount++;

  }

  static void checkNoConflict(
      boolean safe, String conflictDescription, Object entry1, Object entry2) {
    if (!safe) {
      throw conflictException(conflictDescription, entry1, entry2);
    }
  }

  static IllegalArgumentException conflictException(
      String conflictDescription, Object entry1, Object entry2) {
    return new IllegalArgumentException(

  }

  static void checkNoConflict(
      boolean safe, String conflictDescription, Object entry1, Object entry2) {
    if (!safe) {
      throw conflictException(conflictDescription, entry1, entry2);
    }
  }

  static IllegalArgumentException conflictException(
      String conflictDescription, Object entry1, Object entry2) {
    return new IllegalArgumentException(