public boolean containsKey(Object k) {
        PositionalVector pos;
        if (k instanceof CoordinateEntry)
            pos = ((CoordinateEntry) k).asPosition();
        else if (k instanceof PositionalVector)
            pos = (PositionalVector) k;
        else return false;

        for (int i = 0; i < data.length; ++i) {
            CoordinateEntry entry = data[i];
            if (entry.has(pos.getBlockX(), pos.getBlockY(), pos.getBlockZ())) {
                this.lastFetched = i;
                return true;
            }
        }

        return false;
    }