### Question:
Vector extends Tensor<Vector> { @Override public Vector copy() { return new Vector(data.clone()); } Vector(double[] data); static Vector fill(double v, int length); @Override Vector zeros(); @Override Vector copy(); @Override Vector add(Vector b);  }### Answer:
@Test void copiesVector() { Vector vector = new Vector(new double[] { 3D, 2D, 1D}); Vector copy = vector.copy(); assertNotSame(vector, copy); assertArrayEquals(vector.data, copy.data); assertNotSame(vector.data, copy.data); }
@Test void copiesEmptyVector() { Vector vector = new Vector(new double[0]); Vector copy = vector.copy(); assertNotSame(vector, copy); assertArrayEquals(new double[] {}, copy.data); }