old_contents: from django.views.generic import ListView, DetailView, FormView
  
  from forms import TopicCreateForm
  from models import Category, Topic, Forum
  
  
  class CategoryListView(ListView):
      model = Category
  
  class ForumDetailView(DetailView):
      model = Forum
  
  class TopicDetailView(DetailView):
      model = Topic
  
  class TopicCreateView(FormView):
      template_name = 'forums/topic_create.html'
      form_class = TopicCreateForm
  
new_contents: from django.views.generic import ListView, DetailView, FormView
  
  from forms import TopicCreateForm, PostCreateForm
  from models import Category, Topic, Forum
  
  
  class CategoryListView(ListView):
      model = Category
  
  class ForumDetailView(DetailView):
      model = Forum
  
  class TopicDetailView(DetailView):
      model = Topic
  
  class TopicCreateView(FormView):
      template_name = 'forums/topic_create.html'
      form_class = TopicCreateForm
  
  
  class PostCreateView(FormView):
      template_name = 'forums/post_create.html'
      form_class = PostCreateForm
  
subject: implement dummy post create view