This repository contains a basic task.
$ mvn spring-boot:run
$ curl -i -X POST -H "Content-Type:application/json" -d '{ "id": 10001, "firstName" : "lakhan", "lastName" : "Kumar" }' localhost:8080/user
$ curl -X DELETE http://localhost:8080/user/{id}
curl http://localhost:8080/users/{id}
curl -i PUT -H "Content-Type:application/json" -d '{ "id": 10001, "firstName" : "lakhan", "lastName" : "Kumar" }' localhost:8080/user/
##Suggestion Builder I haven't modified the signature as asked, so I guess standard tests that you have designed should work. However to use Collection benefits, I have overrided hashCode() and equals() method of Suggestion class.