code: function (m, u) {
          return [
              m[0][0] * u[0] + m[0][1] * u[1] + m[0][2] * u[2],
              m[1][0] * u[0] + m[1][1] * u[1] + m[1][2] * u[2],
              m[2][0] * u[0] + m[2][1] * u[1] + m[2][2] * u[2]
          ];
      }
docs: Multiplies with a matrix with a vector.
  @method mulMatrixVector
  @param m {Matrix} A matrix
  @param u {Vector} A vector
  @return The resulting vector