Some person IDs are repeated in PRW

[huanglianghua]

For example, in annotations/c1s2_024091.jpg.mat, there are two bounding boxes with the same person ID 297 (but however the two bounding boxes are of different persons).

# The content of c1s2_024091.jpg.mat
-2, 378.513, 465.856, 46.652, 118.963
-2, 408.837, 461.191, 62.981, 144.622
-2, 1124.246, 432.408, 45.419, 135.914
297, 654.389, 624.883, 116.599, 359.318
297, 1327.887, 423.869, 55.983, 151.620
302, 948.536, 459.604, 115.252, 367.094

Is this a mistake or intended? Thanks.