@Override
  protected int indexToAddr(int idx) throws IOException {
    if (myExternalKeysNoMapping) {
      assert idx > 0;
      return idx - KEY_SHIFT;
    }

    int anInt = myCollisionResolutionStorage.getInt(idx);
    if (IntToIntBtree.doSanityCheck) {
      boolean b = anInt >= 0 || myDataDescriptor instanceof InlineKeyDescriptor;
      assert b;
    }
    return anInt;
  }
@Override
  protected int indexToAddr(int idx)