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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def apply_secthresh(self, secthresh, **kwargs):
 """Applies secondary depth constraint to each population See :func:`EclipsePopulation.apply_secthresh`; all arguments passed to that function for each population. """


        if 'secondary depth' not in self.constraints:
            self.constraints.append('secondary depth')
        for pop in self.poplist:
            if not isinstance(pop, EclipsePopulation_Px2):
                pop.apply_secthresh(secthresh, **kwargs)
        self.secthresh = secthresh