what's the purpose of the line "dict(name='right_shoulder',id=3,color=[0, 255, 0],type='upper',swap='left_shoulder')"?

[zssure-thu]

the code below:
dict( name='left_eye', id=1, color=[51, 153, 255], type='upper', swap='right_eye'),
left_eye swap right_eye?why?what does it do?

[jin-s13]

We will use horizontal-flip in data augmentation.
When we flip the image, the left_eye of a person will become the right_eye in the image.

[jin-s13]

This line indicates that the left_eye and the right_eye are a swap/flip pair.

[zssure-thu]

This line indicates that the left_eye and the right_eye are a swap/flip pair.

OK，as i know, the detected posture result is so wired.
for example, in the picture below, all of the right hand's keypoints, left hand's keypoints are correct, but the right wrist(whose index is 10) alone is plotted at left hand toghter with left wrist(whose index is 9)