Consultation about index_TEA，index_IRR and metrics

Hello, may I ask you something about index_TEA，index_IRR and metrics. Thanks for your help. Wish you a good day.

a) Do ```index_TEA = len(metrics)``` (https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park/blob/master/biorefineries/HP/analyses/models_achieved_improvements.py#L857) and ```index_IRR = len(metrics)``` (https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park/blob/master/biorefineries/HP/analyses/models_achieved_improvements.py#L942) return the same value? Because the number of metrics elements seems to be certain (https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park/blob/master/biorefineries/HP/analyses/models_achieved_improvements.py#L130-L547).

b) Could I consult you what do ```index_TEA``` and ```index_IRR``` mean?

c) Are ```metrics``` in a Model a ```tuple``` or a ```list``` (https://biosteam.readthedocs.io/en/latest/API/evaluation/Model.html)? It’s ```tuple``` in https://biosteam.readthedocs.io/en/latest/API/evaluation/Model.html#:~:text=metrics%20(tuple%5BMetric%5D)%20%E2%80%93%20Metrics%20to%20be%20evaluated%20by%20model, but a ```list``` in https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park/blob/master/biorefineries/lactic/models.py#L87-L97, and a ```tuple``` in https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park/blob/master/biorefineries/HP/analyses/models_achieved_improvements.py#L130-L141?