text: import unittest
  import bot
  
  test_input = {
        "currentIntent": {
          "slots": {
            "buyer": "Joe",
            "seller": "John",
            "buyerAddress": None,
          },
          "name": "BillOfSale",
          "confirmationStatus": "None"
        },
        "bot": {
          "alias": "$LATEST",
          "version": "$LATEST",
          "name": "TestBot"
        },
        "userId": "uid",
      #   "invocationSource": "ElicitSlotCodeHook",
        "invocationSource": "FulfillmentCodeHook",
        "outputDialogMode": "Text",
        "messageVersion": "1.0",
        "inputTranscript": "user message",
        "sessionAttributes": {
        }
    }
  
  class LambdaTestCase(unittest.TestCase):
  
      def test_not_none(self):
          """Response is not None"""
          res = bot.lambda_handler(test_input)
          self.assertIsNotNone(res)
  
      def test_fulfillment(self):
          """Response is fulfilled"""
          res = bot.lambda_handler(test_input)
          self.assertEqual(res['dialogAction']['fulfillmentState'], 'Fulfilled')
  
  
  if __name__ == '__main__':
      unittest.main()
  