json response within <speak> is coming as undefined!

[jyo rani]

I am getting this response for my PoST request. Not sure why text between <speak> </speak> is coming as undefined,. can you help?

Response 

{ version: '1.0',

  response:

   { outputSpeech:

      { type: 'SSML',

        ssml:

         '<speak>Great! You have been identified. <break time="200ms"/>undefined</speak>' }

}}}

expected text in the speak tag - "\"Great! You have been identified. <break time=\\\"200ms\\\"/> You can check your balance,So how can I help?\

My script// i am getting response as 200 and all other params are coming as expected.

chai.request(url)

.post('/skxxxxx/ala')

.set(config.headers)

.send(config.pinBodyRequest)

 .end(function(err, res) {

done(err);

})

});

assert.equal(res.status, 200, "Response status not matching")

console.log(res.body)