} else {
      checkArgument(keyEntry == ABSENT, "Key already present: %s", key);
    }

    // insertion point for new entry is after predecessor
    // note predecessor must still be a valid entry: either we deleted an entry that was *not*
    // predecessor, or we didn't delete anything

    ensureCapacity(size + 1);
    keys[size] = key;
    values[size] = value;

    insertIntoTableKToV(size, keyHash);

      return key;
    } else if (oldEntryForKey != null && !force) {
      throw new IllegalArgumentException("key already present: " + key);
    }

    /*
     * The ordering here is important: if we deleted the key entry and then the value entry,
     * the key entry's prev or next pointer might point to the dead value entry, and when we
     * put the new entry in the key entry's position in iteration order, it might invalidate