old_contents: from .likelihood import *
  from .gp import GaussianProcess, ExpSquared, Matern
  
  __all__ = ["LikelihoodFunction", "GaussianProcess", "ExpSquared", "Matern"]
  
new_contents: from .likelihood import *
  from .gp import GaussianProcess, ExpSquared, Matern
  
  __all__ = ["LikelihoodFunction", "GaussianProcess", "ExpSquared"]
  
subject: fix for missing matern object in this branch