old_contents: import os
  from django.core.exceptions import ValidationError
  from django.conf import settings
  
  
  def validate_file_extension(value):
      (_, ext) = os.path.splitext(value.name)
      valid_extensions = settings.SUPPORTED_RESUME_EXTENSIONS
      if not ext.lower() in valid_extensions:
          raise ValidationError('Unsupported file extension.')
  
new_contents: import os
  from django.core.exceptions import ValidationError
  from django.conf import settings
  
  
  def validate_file_extension(value):
      (_, ext) = os.path.splitext(value.name)
      valid_extensions = settings.SUPPORTED_RESUME_EXTENSIONS
      if valid_extensions and not ext.lower() in valid_extensions:
          raise ValidationError('Unsupported file extension.')
  
subject: Fix validator