old_contents: """Forms for Zinnia admin"""
  from django import forms
  from django.db.models import ManyToOneRel
  from django.db.models import ManyToManyRel
  from django.contrib.sites.models import Site
  from django.utils.translation import ugettext_lazy as _
  from django.contrib.admin.widgets import RelatedFieldWidgetWrapper
  
  from mptt.forms import TreeNodeChoiceField
  
  from zinnia.models.entry import Entry
  from zinnia.models.category import Category
  from zinnia.admin.widgets import MPTTFilteredSelectMultiple
  from zinnia.admin.fields import MPTTModelMultipleChoiceField
  
  
  class CategoryAdminForm(forms.ModelForm):
      """Form for Category's Admin"""
      parent = TreeNodeChoiceField(
          label=_('Parent category'),
          level_indicator='|--', required=False,
          empty_label=_('No parent category'),
          queryset=Category.objects.all())
  
      def __init__(self, *args, **kwargs):
          super(CategoryAdminForm, self).__init__(*args, **kwargs)
          rel = ManyToOneRel(Category._meta.get_field('tree_id'),
                             Category, 'id')
          self.fields['parent'].widget = RelatedFieldWidgetWrapper(
              self.fields['parent'].widget, rel, self.admin_site)
  
      def clean_parent(self):
          """Check if category parent is not selfish"""
          data = self.cleaned_data['parent']
          if data == self.instance:
              raise forms.ValidationError(
                  _('A category cannot be parent of itself.'))
          return data
  
      class Meta:
          """CategoryAdminForm's Meta"""
          model = Category
  
  
  class EntryAdminForm(forms.ModelForm):
      """Form for Entry's Admin"""
      categories = MPTTModelMultipleChoiceField(
          label=_('Categories'), required=False,
          queryset=Category.objects.all(),
          widget=MPTTFilteredSelectMultiple(_('categories'), False,
                                            attrs={'rows': '10'}))
  
      def __init__(self, *args, **kwargs):
          super(EntryAdminForm, self).__init__(*args, **kwargs)
          rel = ManyToManyRel(Category, 'id')
          self.fields['categories'].widget = RelatedFieldWidgetWrapper(
              self.fields['categories'].widget, rel, self.admin_site)
          self.fields['sites'].initial = [Site.objects.get_current()]
  
      class Meta:
          """EntryAdminForm's Meta"""
          model = Entry
  
new_contents: """Forms for Zinnia admin"""
  from django import forms
  from django.db.models import ManyToOneRel
  from django.db.models import ManyToManyRel
  from django.contrib.sites.models import Site
  from django.utils.translation import ugettext_lazy as _
  from django.contrib.admin.widgets import RelatedFieldWidgetWrapper
  
  from mptt.forms import TreeNodeChoiceField
  
  from zinnia.models.category import Category
  from zinnia.admin.widgets import MPTTFilteredSelectMultiple
  from zinnia.admin.fields import MPTTModelMultipleChoiceField
  
  
  class CategoryAdminForm(forms.ModelForm):
      """Form for Category's Admin"""
      parent = TreeNodeChoiceField(
          label=_('Parent category'),
          level_indicator='|--', required=False,
          empty_label=_('No parent category'),
          queryset=Category.objects.all())
  
      def __init__(self, *args, **kwargs):
          super(CategoryAdminForm, self).__init__(*args, **kwargs)
          rel = ManyToOneRel(Category._meta.get_field('tree_id'),
                             Category, 'id')
          self.fields['parent'].widget = RelatedFieldWidgetWrapper(
              self.fields['parent'].widget, rel, self.admin_site)
  
      def clean_parent(self):
          """Check if category parent is not selfish"""
          data = self.cleaned_data['parent']
          if data == self.instance:
              raise forms.ValidationError(
                  _('A category cannot be parent of itself.'))
          return data
  
  
  class EntryAdminForm(forms.ModelForm):
      """Form for Entry's Admin"""
      categories = MPTTModelMultipleChoiceField(
          label=_('Categories'), required=False,
          queryset=Category.objects.all(),
          widget=MPTTFilteredSelectMultiple(_('categories'), False,
                                            attrs={'rows': '10'}))
  
      def __init__(self, *args, **kwargs):
          super(EntryAdminForm, self).__init__(*args, **kwargs)
          rel = ManyToManyRel(Category, 'id')
          self.fields['categories'].widget = RelatedFieldWidgetWrapper(
              self.fields['categories'].widget, rel, self.admin_site)
          self.fields['sites'].initial = [Site.objects.get_current()]
  
subject: Remove the Meta option class for removing DeprecationWarning