}
    } else {
      checkArgument(valueEntry == ABSENT, "Value already present: %s", value);
    }

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

    insertIntoTableKToV(size, keyHash);
    insertIntoTableVToK(size, valueHash);

    setSucceeds(lastInInsertionOrder, size);
    setSucceeds(size, ENDPOINT);
    size++;
    modCount++;
    return null;
  }