docs: def write_alf_params_(self):
          """ DEPRECATED """
          if not hasattr(self, 'alf_dirs'):
              self.make_alf_dirs()
  
          if not hasattr(self, 'class_trees'):
              self.generate_class_trees()
  
          alf_params = {}
          for k in range(self.num_classes):
              alfdir = self.alf_dirs[k + 1]
              tree = self.class_trees[k + 1]
              datatype = self.datatype
              name = 'class{0}'.format(k + 1)
              num_genes = self.class_list[k]
              seqlength = self.gene_length_min
              gene_length_kappa = self.gene_length_kappa
              gene_length_theta = self.gene_length_theta
              alf_obj = ALF(tree=tree,
                            datatype=datatype, num_genes=num_genes,
                            seqlength=seqlength, gene_length_kappa=gene_length_kappa,
                            gene_length_theta=gene_length_theta, name=name, tmpdir=alfdir)
              if datatype == 'protein':
                  alf_obj.params.one_word_model('WAG')
              else:
                  alf_obj.params.jc_model()
              alf_params[k + 1] = alf_obj
  
          self.alf_params = alf_params