Applies constraint corresponding to RV trend non-detection to each population

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

def apply_trend_constraint(self, limit, dt, **kwargs):
        """
        Applies constraint corresponding to RV trend non-detection to each population

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

        """
        if 'RV monitoring' not in self.constraints:
            self.constraints.append('RV monitoring')
        for pop in self.poplist:
            if not hasattr(pop,'dRV'):
                continue
            pop.apply_trend_constraint(limit, dt, **kwargs)
        self.trend_limit = limit
        self.trend_dt = dt