new_contents: from unittest import TestCase
  
  import pymongo
  from mongotools import pubsub
  
  class TestOplog(TestCase):
  
      def setUp(self):
          self.bind = pymongo.MongoClient()
          self.tail = pubsub.OplogTail(self.bind)
  
      def test_cursor_explain(self):
          cur = self.tail.cursor(await=False)
          plan = cur.explain()
          self.assertEqual(plan['cursor'], 'ForwardCappedCursor')
  
      def test_cursor_await_explain(self):
          cur = self.tail.cursor(await=True)
          plan = cur.explain()
          self.assertEqual(plan['cursor'], 'ForwardCappedCursor')
  
  
subject: Add missing test file