How to use skip_frames

I want to see the frames after top 3000 frames, I use
```
vr.skip_frames(3000)
vr.seek(0)
vr.next()
```
However, it is played from start.

I use this code and it works, but it is slow.
```
for i in range(0, len(vr)):
if i < 3000:
continue
img = vr[i]
```

I want to figure out how to use skip_frames.
Thanks !