code: def _init_required_options(self, **kwargs):
          
          for field in self.required_options:
              setattr(self, field, kwargs.get(field))
              self._store_option(field)
docs: Initialize the required option as class members. The value will be
          either None or the specified value in the kwargs or __init__. The logic
          here is to make the required options accesible to edit after a class
          instance has been created.