old_contents: from django.contrib.admin import ModelAdmin
  
  
  def grading_schemes(grading):
      ''' The list of grading schemes using this grading.'''
      return ",\n".join([scheme for scheme in grading.schemes.all()])
  
  
  def means_passed(grading):
      return grading.means_passed
  
  
  means_passed.boolean = True
  
  
  class GradingAdmin(ModelAdmin):
      list_display = ['__str__', grading_schemes, means_passed]
  
      class Media:
          css = {'all': ('css/teacher.css',)}
  
new_contents: from django.contrib.admin import ModelAdmin
  
  
  def grading_schemes(grading):
      ''' The list of grading schemes using this grading.'''
      return ",\n".join([str(scheme) for scheme in grading.schemes.all()])
  
  
  def means_passed(grading):
      return grading.means_passed
  
  
  means_passed.boolean = True
  
  
  class GradingAdmin(ModelAdmin):
      list_display = ['__str__', grading_schemes, means_passed]
  
      class Media:
          css = {'all': ('css/teacher.css',)}
  
subject: Fix bug