Applies velocity contrast curve constraint to each population

        See :func:`vespa.stars.StarPopulation.apply_vcc`;
        all arguments passed to that function for each population.

def apply_vcc(self,vcc):
        """
        Applies velocity contrast curve constraint to each population

        See :func:`vespa.stars.StarPopulation.apply_vcc`;
        all arguments passed to that function for each population.

        """
        if 'secondary spectrum' not in self.constraints:
            self.constraints.append('secondary spectrum')
        for pop in self.poplist:
            if not pop.is_specific:
                try:
                    pop.apply_vcc(vcc)
                except:
                    logging.info('VCC constraint not applied to %s model' % (pop.model))