old_contents: from .liftingline import *
  from .data.geometry import Section, BaseWing, Wing
  from .analysis import LiftAnalysis, LiftAndMomentAnalysis
  from .airfoil import Airfoil
  from .mass import Masspoint
  
new_contents: from .liftingline import *
  from data.geometry import Section, BaseWing, Wing
  from .analysis import LiftAnalysis, LiftAndMomentAnalysis
  from .airfoil import Airfoil
  from .mass import Masspoint
  
subject: Update __init__.py