old_contents: from .acidity import Acidity # noqa
  from .niche import Niche # noqa
  from .nutrient_level import NutrientLevel # noqa
  from .vegetation import Vegetation # noqa
  from .version import __version__ # noqa
  
new_contents: from .acidity import Acidity # noqa
  from .niche import Niche, NicheDelta # noqa
  from .nutrient_level import NutrientLevel # noqa
  from .vegetation import Vegetation # noqa
  from .version import __version__ # noqa
  
subject: Add NicheDelta to namespace