new_contents: #!/usr/bin/env python
  
  from __future__ import absolute_import
  from __future__ import print_function
  
  import os
  import sys
  
  our_dir = os.path.dirname(os.path.abspath(__file__))
  # For dev setups, we can find the API in the repo itself.
  if os.path.exists(os.path.join(our_dir, '..')):
      sys.path.insert(0, '..')
  from bots_test_lib import BotTestCase
  
  class TestHelloWorldBot(BotTestCase):
      bot_name = "helloworld"
  
      def test_bot(self):
          self.assert_bot_output(
              {'content': "foo", 'type': "private", 'sender_email': "foo"},
              "beep boop"
          )
          self.assert_bot_output(
              {'content': "Hi, my name is abc", 'type': "stream", 'display_recipient': "foo", 'subject': "foo"},
              "beep boop"
          )
          self.assert_bot_output(
              {'content': "", 'type': "stream", 'display_recipient': "foo", 'subject': "foo"},
              "beep boop"
          )
  
subject: Add tests for helloworld bot in contrib_bots.