boolean pruneLeftEdgeValue(final long page) throws PersistitException {
        _ignoreTransactions = true;
        Buffer buffer = null;
        try {
            buffer = _pool.get(_volume, page, false, true);
            buffer.clearEnqueuedForPruning();
            long at = buffer.at(Buffer.KEY_BLOCK_START);
            if (at > 0) {
                int offset = (int) (at >>> 32);
                int size = (int) at;
                if (size == 1 && buffer.getBytes()[offset] == MVV.TYPE_ANTIVALUE) {
                    buffer.nextKey(_spareKey1, Buffer.KEY_BLOCK_START);
                    buffer.release();
                    buffer = null;
                    _spareKey1.copyTo(_spareKey2);
                    _spareKey2.nudgeDeeper();
                    raw_removeKeyRangeInternal(_spareKey1, _spareKey2, false, true);
                    return true;
                }
            }
            return false;
        } finally {
            if (buffer != null) {
                buffer.release();
            }
        }
    }