Recall that for the 1-NN rule, the region associated with a feature vector xi is the set of all points that are closer to xi than to any of the other feature vectors xj for j = i. These are the Voronoi regions. Sketch the Voronoi regions for feature vectors x1 = (0, 0), x2 = (0, 2), x3 = (2, 0), and x4 = (1, 1).