code: def individuals(self, ind_ids=None):
          
          if ind_ids:
              for ind_id in ind_ids:
                  for ind in self.individual_objs:
                      if ind.ind_id == ind_id:
                          yield ind
          else:
              for ind in self.individual_objs:
                  yield ind
docs: Return information about individuals
          
              Args:
                  ind_ids (list(str)): List of individual ids
              
              Returns:
                  individuals (Iterable): Iterable with Individuals