docs: def apply_cc(self, cc, distribution_skip=False,
                   **kwargs):
          """
          Apply contrast-curve constraint to population.
  
          Only works if object has ``Rsky``, ``dmag`` attributes
  
          :param cc:
              Contrast curve.
          :type cc:
              :class:`ContrastCurveConstraint`
  
          :param distribution_skip:
              This is by default ``True``.  *To be honest, I'm not
              exactly sure why.  Might be important, might not
              (don't remember).*
  
          :param **kwargs:
              Additional keyword arguments passed to
              :func:`StarPopulation.apply_constraint`.
  
          """
          rs = self.Rsky.to('arcsec').value
          dmags = self.dmag(cc.band)
          self.apply_constraint(ContrastCurveConstraint(rs,dmags,cc,name=cc.name),
                                distribution_skip=distribution_skip, **kwargs)