class SparseVector extends Vector {

    @Override
    public VectorIterator iterator() {
        return new SparseVectorVectorIterator();
    }

    public  SparseVector();
    public  SparseVector(int n);
    public  SparseVector(int n, int[] indices, double[] values);
    public  SparseVector(int n, Map<Integer, Double> kv);

}