How to use the pyccl.halos.MassDef function in pyccl

if not massdef in self.mdef_dict:
            raise ValueError (f"Halo density profile mass definition {massdef} not currently supported")

        # Check if we have already an instance of the required object, if not create one
        if not ((halo_profile_model == self.halo_profile_model) and (massdef == self.massdef) and (delta_mdef == self.delta_mdef)):
            self.halo_profile_model = halo_profile_model
            self.massdef = massdef
            
            cur_cdelta = 0.0
            cur_mdelta = 0.0
            cur_values = False
            if self.hdpm:
                cur_cdelta = self.conc.c
                cur_values = True
            
            self.mdef = ccl.halos.MassDef (delta_mdef, self.mdef_dict[massdef])
            self.conc = ccl.halos.ConcentrationConstant (self.mdef)
            self.mdef.concentration = self.conc
            self.hdpm = self.hdpm_dict[halo_profile_model] (self.conc, **self.hdpm_opts[halo_profile_model])
            if cur_values:
                self.conc.c = cur_cdelta