private void setKeyAt(int i, int value) throws IOException {
      final int offset = indexToOffset(i) + KEY_OFFSET;
      if (doSanityCheck) {
        final int metaPageLen;
        if (isHashedLeaf()) {
          assert i < hashPageCapacity;
          metaPageLen = metaDataLeafPageLength;
        }
        else {
          assert i < getChildrenCount();
          metaPageLen = RESERVED_META_PAGE_LEN;
        }
        assert offset + 4 <= pageSize;
        assert offset >= metaPageLen;
      }
      putInt(offset, value);
    }
private void setKeyAt(int i, int value)