About the value of tokens_positive in grounding dino

[Jackluisus]

Hello，I want to know how the value of token_positive is obtained.

Here is the example from Goldg datasets:
{"filename": "3359636318.jpg", "height": 334, "width": 500, "grounding": {"caption": "Two people are talking outside of the video game shop next door to the mobile phone store .", "regions": [{"bbox": [[144.0, 166.0, 208.0, 334.0], [47.0, 183.0, 106.0, 334.0]], "phrase": "Two people", "tokens_positive": [[0, 10]]}, {"bbox": [192.0, 1.0, 499.0, 231.0], "phrase": "the mobile phone store", "tokens_positive": [[67, 89]]}, {"bbox": [1.0, 55.0, 169.0, 308.0], "phrase": "the video game shop", "tokens_positive": [[34, 53]]}]}}