old_contents: import email
  from os.path import dirname, join
  
  from django.utils import six
  from django_mailbox.models import Mailbox
  
  from feder.letters.signals import MessageParser
  
  
  class MessageMixin(object):
      def setUp(self):
          self.mailbox = Mailbox.objects.create(from_email='from@example.com')
          super(MessageMixin, self).setUp()
  
      @staticmethod
      def _get_email_path(filename):
          return join(dirname(__file__), 'messages', filename)
  
      @staticmethod
      def _get_email_object(filename):  # See coddingtonbear/django-mailbox#89
          path = MessageMixin._get_email_path(filename)
          for line in open('git-lfs.github.com', 'r'):
              if 'git-lfs' in line:
                  raise new Exception("File '{}' not downloaded. Only Git-LFS reference available. Perform 'git lfs pull'.".format(filename))
          if six.PY3:
              return email.message_from_file(open(path, 'r'))
          else: # Deprecated. Back-ward compatible for PY2.7<
              return email.message_from_file(open(path, 'rb'))
  
      def get_message(self, filename):
          message = self._get_email_object(filename)
          msg = self.mailbox._process_message(message)
          msg.save()
          return msg
  
      def load_letter(self, name):
          message = self.get_message(name)
          return MessageParser(message).insert()
  
new_contents: import email
  from os.path import dirname, join
  
  from django.utils import six
  from django_mailbox.models import Mailbox
  
  from feder.letters.signals import MessageParser
  
  
  class MessageMixin(object):
      def setUp(self):
          self.mailbox = Mailbox.objects.create(from_email='from@example.com')
          super(MessageMixin, self).setUp()
  
      @staticmethod
      def _get_email_path(filename):
          return join(dirname(__file__), 'messages', filename)
  
      @staticmethod
      def _get_email_object(filename):  # See coddingtonbear/django-mailbox#89
          path = MessageMixin._get_email_path(filename)
          for line in open('git-lfs.github.com', 'r'):
              if 'git-lfs' in line:
                  raise Exception("File '{}' not downloaded. Only Git-LFS reference available. Perform 'git lfs pull'.".format(filename))
          if six.PY3:
              return email.message_from_file(open(path, 'r'))
          else: # Deprecated. Back-ward compatible for PY2.7<
              return email.message_from_file(open(path, 'rb'))
  
      def get_message(self, filename):
          message = self._get_email_object(filename)
          msg = self.mailbox._process_message(message)
          msg.save()
          return msg
  
      def load_letter(self, name):
          message = self.get_message(name)
          return MessageParser(message).insert()
  
subject: Fix detect Git-LFS in tests