NPE for wrong clientSecret during TokenAccess #29

It was not showing correct message for wrong clientSecret rather throwing NPE. When i checked in code If response is not 200 then you are parsing it to TokenResponseException . You are creating instance of TokenResponseException by using response.getContent() and failing in JsonParser(below is code) because content is returning null .
public JsonParser createJsonParser(InputStream in, Charset charset) throws IOException { Preconditions.checkNotNull(in);
return new JacksonParser(this, this.factory.createJsonParser(in)); }
SS attached.

More Details:
http://stackoverflow.com/questions/41012392/unauthorized-error-in-uber-token-api