old_contents: 
  from django import forms
  from . import models
  
  
  class NewOverallForm(forms.ModelForm):
      class Meta:
          model = models.Course
          fields = ['title']
new_contents: 
  from django import forms
  from . import models
  
  
  class NewOverallForm(forms.ModelForm):
      class Meta:
          model = models.Course
          fields = ['title']
          
  
subject: Update forms.py