\text { For the vector field } \vec{E}=\hat{x} x z-\hat{y} y z^{2}-\hat{z} x y \text {, verify the divergence theorem by computing: } (a) The total outward flux flowing through the surface of a cube centered at the origin and with sides equal to 2 units each and parallel to the Cartesian axes, and (b) The integral of V.E over the cube's volume