def METHOD_NAME(self, H, W, offset=20):
    shape = np.random.choice(self.class_names[1:])
    color = tuple(np.random.randint(0, 255, size=3).tolist())
    center_x = np.random.randint(offset, W - offset - 1)
    center_y = np.random.randint(offset, H - offset - 1)
    size = np.random.randint(offset, H // 4)
    return shape, color, (center_x, center_y, size)