code: def include_feature(self, name):
          
  
          if self.feature_is_included(name) == 0:
              descr = self.features[name].description
              raise DistutilsOptionError(
                  descr + " is required, but was excluded or is not available"
              )
          self.features[name].include_in(self)
          self._set_feature(name, 1)
docs: Request inclusion of feature named 'name