old_contents: import re
  from django import forms
  from fluent_contents.forms import ContentItemForm
  
  
  class TwitterEmbedAdminForm(ContentItemForm):
      def clean_twitter_url(self):
          """
          Make sure the URL provided matches the twitter URL format.
          """
          url = self.cleaned_data['twitter_url']
  
          if url:
              pattern = re.compile(r'https?://(www\.)?twitter.com/\S+/status(es)?/\S+')
              if not pattern.match(url):
                  raise forms.ValidationError('Please provide a valid twitter link.')
  
          return url
  
  
new_contents: import re
  from django import forms
  from fluent_contents.forms import ContentItemForm
  from icekit.plugins.twitter_embed.models import TwitterEmbedItem
  
  
  class TwitterEmbedAdminForm(ContentItemForm):
      class Meta:
          model = TwitterEmbedItem
          fields = '__all__'
  
      def clean_twitter_url(self):
          """
          Make sure the URL provided matches the twitter URL format.
          """
          url = self.cleaned_data['twitter_url']
  
          if url:
              pattern = re.compile(r'https?://(www\.)?twitter.com/\S+/status(es)?/\S+')
              if not pattern.match(url):
                  raise forms.ValidationError('Please provide a valid twitter link.')
  
          return url
  
subject: Add model and firld information to form.