Dear author, I am writing to seek your help regarding an issue I encountered while studying tkwant. Specifically, when trying to calculate the Green functions, I got an error message "AttributeError: module 'tkwant.manybody' has no attribute 'GreenFunction'". I was wondering if you could kindly explain to me what may be the cause of this error.
Thank you very much for your time and attention. I greatly appreciate any guidance you could provide.
