code: def obfn_gvar(self):
          
  
          # Get inner cbpdn object gvar
          gv = self.inner_obfn_gvar().copy()
          # Set slice corresponding to the coefficient map of the final
          # filter (the impulse inserted for the AMS method) to zero so
          # that it does not affect the results (e.g. l1 norm) computed
          # from this variable by the inner cbpdn object
          gv[..., -self.cri.Cd:] = 0
  
          return gv
docs: This method is inserted into the inner cbpdn object,
          replacing its own obfn_gvar method, thereby providing a hook for
          applying the additional steps necessary for the AMS method.