docs: def apply_cc(self, cc, **kwargs):
          """
          Applies contrast curve constraint to each population
  
          See :func:`vespa.stars.StarPopulation.apply_cc`;
          all arguments passed to that function for each population.
  
          """
          if type(cc)==type(''):
              pass
          if cc.name not in self.constraints:
              self.constraints.append(cc.name)
          for pop in self.poplist:
              if not pop.is_specific:
                  try:
                      pop.apply_cc(cc, **kwargs)
                  except AttributeError:
                      logging.info('%s cc not applied to %s model' % (cc.name,pop.model))