code: def handle_aliases_in_init_files(name, import_alias_mapping):
      
      for key, val in import_alias_mapping.items():
          # e.g. Foo == Foo
          # e.g. Foo.Bar startswith Foo.
          if name == val or \
                  name.startswith(val + '.'):
  
              # Replace val with key in name
              # e.g. StarbucksVisitor.Tea -> Eataly.Tea because
              #   "from .nested_folder import StarbucksVisitor as Eataly"
              return name.replace(val, key)
      return None
docs: Returns either None or the handled alias.
      Used in add_module.